Senior Software Developer - Java, microservices, C++
Aktualisiert am 15.04.2026
Profil
Freiberufler / Selbstständiger
Remote-Arbeit
Verfügbar ab: 19.04.2026
Verfügbar zu: 100%
davon vor Ort: 20%
Java
Spring Boot
Microservices
C++
Rust

Einsatzorte

Einsatzorte

Deutschland, Schweiz
möglich

Projekte

Projekte

3 years 2 months
2023-01 - 2026-02

Intelligent Copy-Trading & Vault Aggregation Platform on Hyperliquid DEX

Founder & Principal Software Engineer Java 21 Spring Boot 4.0 Apache Kafka ...
Founder & Principal Software Engineer
Architected and implemented a production-grade Intelligent Copy-Trading & Vault Aggregation Platform on Hyperliquid DEX ? a microservice-based event-driven system targeting sub-500ms p99 end-to-end copy-trade latency (leader fill to follower order submission), 10,000 copy-trade events per second, 99.95% platform availability, and up to 10,000 concurrent followers per leader.
  • Platform Architecture & Data Infrastructure: Decomposed the platform into 12 single-responsibility Spring Boot microservices over a 16-topic Kafka backbone ? partitioned up to 64 for follower order parallelism ? Standardized cross-service concerns (Virtual Thread configuration, Flyway migrations, Avro serialization) through a shared Gradle convention plugin, reducing per-service boilerplate and enforcing consistency across the deployment surface.
  • Built a fault-tolerant WebSocket ingestion layer using an LMAX Disruptor ring buffer as the backpressure boundary between Netty's reactive inbound thread and downstream Kafka producers ? L2 orderbook snapshots dropped first under saturation while fills and trades are guaranteed delivery ? with exponential backoff reconnection preventing thundering herd against exchange rate limits.
  • Analytics Pipeline & Real-Time Leaderboards: Designed a Kafka Streams topology consuming fill events rekeyed by wallet address over 24-hour tumbling windows, producing daily performance snapshots ? Leaderboards maintained as Redis sorted sets decoupled from the analytical database, supporting latencysensitive ranking queries for the follower-facing discovery experience
Java 21 Spring Boot 4.0 Apache Kafka Kafka Streams Spring Cloud Gateway Resilience4j LMAX Disruptor Redis PostgreSQL + TimescaleDB Web3j (EIP-712) Apache Avro + Confluent Schema Registry Prometheus Grafana Testcontainers
on request
4 years 5 months
2021-10 - 2026-02

HFT engine targeting cryptocurrency perpetuals and spot markets

Founder & Principal Software Engineer C++23 gcc CMake ...
Founder & Principal Software Engineer
Designed and implemented a production-grade sub-100?s p99 tick-to-trade High Frequency Trading system in C++23 targeting cryptocurrency perpetuals and spot markets. System architecture prioritizes deterministic latency over throughput, with zero heap allocation, zero syscalls, and zero virtual dispatch on the critical path.
  • System Architecture: Built a microservice-based event-driven pipeline with strict single-responsibility boundaries ? Enabling independent deployment, isolated fault domains, and sub-component latency profiling. Each service operates on dedicated cores with well-defined data contracts.
  • Inter-Process Communication: Implemented lock-free shared memory queues (SPSC ring buffers) achieving zero-copy, zero-kernel-crossing message passing on the hot path. Sequenced writes with cache-line padding eliminate false sharing
  • Designed bare-metal Linux tuning framework for ultra-low-latency trading infrastructure, reducing p99.9 jitter by ~98% ? bypassing OS scheduling on isolated hot-path cores via kernel boot parameters, disabling SMT/turbo/C-states, allocating 32 GB huge pages, pinning IRQs off trading cores, tuning NICs for minimal kernel-to-wire latency and building a foundation for future kernel-bypass and FPGA-accelerated feed handling
  • Optimized market data parsing by first evaluating simdjson to then find out its tape-based architecture is incompatible with sub-?s latency targets. Built custom zero-allocation JSON parser from scratch deserializing directly into cache-aligned POD structs ? eliminating intermediate representation, enabling fixed-offset field extraction, and achieving deterministic ~200ns parse latency for exchange messages.
  • Robust and resilient exchange connectivity: Implemented fault-tolerant multiplexed WebSocket connections with exponential backoff + configurable jitter on reconnection ? preventing thundering herd on exchange rate limits while maintaining 99.9%+ feed uptime.
C++23 gcc CMake Boost.Asio + Boost.Beast Websockets Google Test + Google Benchmark Ansible deployment systemd service management perf flamegraph RDTSC Prometheus Grafana Templates
on request
1 year 9 months
2019-07 - 2021-03

B2B corporate payment platform

Senior Software Developer Java 8 async-profiler Spring Boot ...
Senior Software Developer
Architected and delivered mission-critical, event-driven microservices for a B2B corporate payment platform serving 55,000+ enterprise clients across 57 countries, enabling real-time virtual card provisioning that reduced card issuance from days to under 30 seconds.
  • Architected and delivered fault-tolerant, event-driven microservices processing 1.3M+ virtual card transactions and 18M+ travel ticket payments annually at 99.9% uptime. Designed the real-time card authorization critical path (Spring Boot, Spring Kafka) with strict latency budgets ? optimized hot-path services to sub-15ms p99 authorization response times through connection pool tuning and elimination of synchronous blocking calls on the transaction thread.
  • Instrumented and optimized Kafka consumer group performance across the transaction processing pipeline, implementing partition-aware batching and back-pressure mechanisms that maintained sub-100ms consumer lag under peak booking volumes. Profiled JVM allocation rates on hot-path consumers using async-profiler, identified and eliminated major allocation sites in the serialization layer ? reducing GC pressure by ~60% and achieving consistent processing latency during peak-hour traffic spikes. 
  • Drove technology selection and architectural decisions across the platform engineering team, including the evaluation and adoption of Apache Kafka over legacy JMS messaging ? structuring the evaluation as a mentoring exercise for junior engineers (throughput benchmarks, failure recovery semantics, schema evolution trade-offs).
Java 8 async-profiler Spring Boot Spring Kafka Apache Kafka Hadoop Azure Kubernetes Docker Helm Jenkins Git
Lufthansa Airplus Servicekarten GmbH
1 year 6 months
2018-01 - 2019-06

Traveler Information System (RIS)

Senior Software Engineer Java 8 Spring boot Multithreading ...
Senior Software Engineer
Architected and delivered mission-critical components of the RI-Platform (Traveler information system), a centralized real-time data platform serving millions of daily passengers across thousands of trains, processing hundreds of millions of events daily with 99.9% availability.
  • Architected and owned event-driven microservices within a ~100-microservice ecosystem, processing 60M daily tracking incidents from signaling systems, GPS, and IoT sensors to deliver real-time train positioning, delay forecasts, and platform assignments to 800+ stations. Led the technical design of the ingestion layer, defining latency budgets, partitioning strategies, and data contracts across upstream signal providers and downstream consumer services.
  • Built high-throughput Kafka Streams pipelines achieving sub-second data propagation to 6,600+ display devices. Profiled and optimized JVM performance across latency-critical consumer services ? tuned G1GC pause targets, heap generation sizing, and thread-to-core affinity via JNI ? reducing p99 processing latency by ~40% and eliminating GC-induced stalls during peak traffic.
  • Replaced Jackson-based JSON serialization on high-throughput Kafka event streams with optimized binary encoding, reducing per-message serialization overhead by ~75% and eliminating allocation pressure on the critical ingestion path. Evaluated SBE and FlatBuffers against schema evolution requirements and downstream consumer compatibility, selecting the approach that balanced latency gains with the team's operational constraints.
  • Observability: Implemented comprehensive monitoring (Prometheus, Grafana, Elastic Stack) for real-time system health across distributed microservices, supporting the platform's "you build it, you run it" DevOps culture within a 110-engineer, 13-scrum-team organization
Java 8 Spring boot Multithreading Low latency GC tuning Python Apache Kafka Kafka Streams Apache NiFi Hadoop/HDFS MongoDB Docker Kubernetes AWS Elastic Stack Prometheus Grafana Jenkins
Deutsche Bahn
2 years 8 months
2015-03 - 2017-10

Big Data infrastructure for the Corporate and Investment Bank

Software Development Engineer Java Spring Boot JMS ...
Software Development Engineer

Contributed to the architecture and delivery of a mission-critical Big Data infrastructure for the Corporate and Investment Bank, enabling real-time counterparty exposure tracking, risk aggregation, and regulatory reporting across Deutsche Bank's global trading and banking operations.

  • Contributed to the design and implementation of an enterprise data lake covering Liquidity, Credit Risk, Collateral Management, and Counterparty Exposure?consolidating risk data from siloed legacy systems into a unified platform. Supported the bank's strategic goal of creating a single source of truth for risk data aggregation across multiple databases and multiple business divisions, directly addressing regulatory requirements.
  • Developed high-throughput Java/Spring services exposing aggregated risk and exposure data to downstream consumers including Finance, Risk Management, and Regulatory Reporting systems
  • Collaborated on ETL solutions consolidating Balance Sheet and P&L data across business divisions, powering management and regulatory reporting. Platform enabled 30%+ reduction in manual reconciliation effort and accelerated time-to-report for stress testing and capital adequacy submissions.
  • Contributed to the bank's operational efficiency program through automation of data workflows, reduction of manual processes, and standardization of data governance practices across the Corporate Bank and Investment Bank divisions.

Java Spring Boot JMS Apache Storm Apache Spark Hadoop/HDFS Hive MarkLogic Multithreading RESTful Web Services Git Jenkins CI/CD Scrum/Agile
Deutsche Bank
Frankfurt and London

Aus- und Weiterbildung

Aus- und Weiterbildung

1 year 6 months
2013-10 - 2015-03

Information Systems

MSc Computer Science (1.6), Technical University Munich, Germany
MSc Computer Science (1.6)
Technical University Munich, Germany

Position

Position

Senior Software Developer

Kompetenzen

Kompetenzen

Top-Skills

Java Spring Boot Microservices C++ Rust

Produkte / Standards / Erfahrungen / Methoden

Profile

Senior Software Engineer with 10+ years of experience across finance and payments, transport and logistics, and proprietary trading ? specializing in latency-critical distributed systems and event-driven microservice architectures in Java, C++ and Rust. Architected high-throughput platforms spanning real-time risk aggregation, large-scale data systems (180M events/day), and mission-critical payment infrastructure serving 55,000+ enterprise clients. As founder-engineer, designed and delivered production trading systems end-to-end: sub-100?s tick-to-trade engines, a microservice-based Spring Boot platform on a Kafka backbone processing 10,000 events/second at sub-500ms p99. Technical leader who drives architectural decisions, establishes performance engineering culture, and scales teams through structured mentoring.


Skills:

System & Architecture:

  • Low-latency systems
  • Event-driven microservices
  • Lock-free & zeroallocation pipelines
  • Real-time data processing
  • Distributed systems
  • JVM performance tuning
  • Low-level programming


Data & Messaging:

  • Apache Kafka
  • Redis
  • PostgreSQL
  • TimescaleDB
  • Apache Avro
  • MongoDB


Frameworks & Software:

  • Spring Boot
  • Spring Kafka
  • Spring Cloud Gateway
  • Kafka Streams


DevOps:

  • AWS
  • Azure
  • Docker
  • Kubernetes
  • Helm
  • CI/CD
  • Ansible
  • Maven
  • Gradle

Programmiersprachen

java
Experte
C++
Fortgeschritten
Rust
Fortgeschritten

Einsatzorte

Einsatzorte

Deutschland, Schweiz
möglich

Projekte

Projekte

3 years 2 months
2023-01 - 2026-02

Intelligent Copy-Trading & Vault Aggregation Platform on Hyperliquid DEX

Founder & Principal Software Engineer Java 21 Spring Boot 4.0 Apache Kafka ...
Founder & Principal Software Engineer
Architected and implemented a production-grade Intelligent Copy-Trading & Vault Aggregation Platform on Hyperliquid DEX ? a microservice-based event-driven system targeting sub-500ms p99 end-to-end copy-trade latency (leader fill to follower order submission), 10,000 copy-trade events per second, 99.95% platform availability, and up to 10,000 concurrent followers per leader.
  • Platform Architecture & Data Infrastructure: Decomposed the platform into 12 single-responsibility Spring Boot microservices over a 16-topic Kafka backbone ? partitioned up to 64 for follower order parallelism ? Standardized cross-service concerns (Virtual Thread configuration, Flyway migrations, Avro serialization) through a shared Gradle convention plugin, reducing per-service boilerplate and enforcing consistency across the deployment surface.
  • Built a fault-tolerant WebSocket ingestion layer using an LMAX Disruptor ring buffer as the backpressure boundary between Netty's reactive inbound thread and downstream Kafka producers ? L2 orderbook snapshots dropped first under saturation while fills and trades are guaranteed delivery ? with exponential backoff reconnection preventing thundering herd against exchange rate limits.
  • Analytics Pipeline & Real-Time Leaderboards: Designed a Kafka Streams topology consuming fill events rekeyed by wallet address over 24-hour tumbling windows, producing daily performance snapshots ? Leaderboards maintained as Redis sorted sets decoupled from the analytical database, supporting latencysensitive ranking queries for the follower-facing discovery experience
Java 21 Spring Boot 4.0 Apache Kafka Kafka Streams Spring Cloud Gateway Resilience4j LMAX Disruptor Redis PostgreSQL + TimescaleDB Web3j (EIP-712) Apache Avro + Confluent Schema Registry Prometheus Grafana Testcontainers
on request
4 years 5 months
2021-10 - 2026-02

HFT engine targeting cryptocurrency perpetuals and spot markets

Founder & Principal Software Engineer C++23 gcc CMake ...
Founder & Principal Software Engineer
Designed and implemented a production-grade sub-100?s p99 tick-to-trade High Frequency Trading system in C++23 targeting cryptocurrency perpetuals and spot markets. System architecture prioritizes deterministic latency over throughput, with zero heap allocation, zero syscalls, and zero virtual dispatch on the critical path.
  • System Architecture: Built a microservice-based event-driven pipeline with strict single-responsibility boundaries ? Enabling independent deployment, isolated fault domains, and sub-component latency profiling. Each service operates on dedicated cores with well-defined data contracts.
  • Inter-Process Communication: Implemented lock-free shared memory queues (SPSC ring buffers) achieving zero-copy, zero-kernel-crossing message passing on the hot path. Sequenced writes with cache-line padding eliminate false sharing
  • Designed bare-metal Linux tuning framework for ultra-low-latency trading infrastructure, reducing p99.9 jitter by ~98% ? bypassing OS scheduling on isolated hot-path cores via kernel boot parameters, disabling SMT/turbo/C-states, allocating 32 GB huge pages, pinning IRQs off trading cores, tuning NICs for minimal kernel-to-wire latency and building a foundation for future kernel-bypass and FPGA-accelerated feed handling
  • Optimized market data parsing by first evaluating simdjson to then find out its tape-based architecture is incompatible with sub-?s latency targets. Built custom zero-allocation JSON parser from scratch deserializing directly into cache-aligned POD structs ? eliminating intermediate representation, enabling fixed-offset field extraction, and achieving deterministic ~200ns parse latency for exchange messages.
  • Robust and resilient exchange connectivity: Implemented fault-tolerant multiplexed WebSocket connections with exponential backoff + configurable jitter on reconnection ? preventing thundering herd on exchange rate limits while maintaining 99.9%+ feed uptime.
C++23 gcc CMake Boost.Asio + Boost.Beast Websockets Google Test + Google Benchmark Ansible deployment systemd service management perf flamegraph RDTSC Prometheus Grafana Templates
on request
1 year 9 months
2019-07 - 2021-03

B2B corporate payment platform

Senior Software Developer Java 8 async-profiler Spring Boot ...
Senior Software Developer
Architected and delivered mission-critical, event-driven microservices for a B2B corporate payment platform serving 55,000+ enterprise clients across 57 countries, enabling real-time virtual card provisioning that reduced card issuance from days to under 30 seconds.
  • Architected and delivered fault-tolerant, event-driven microservices processing 1.3M+ virtual card transactions and 18M+ travel ticket payments annually at 99.9% uptime. Designed the real-time card authorization critical path (Spring Boot, Spring Kafka) with strict latency budgets ? optimized hot-path services to sub-15ms p99 authorization response times through connection pool tuning and elimination of synchronous blocking calls on the transaction thread.
  • Instrumented and optimized Kafka consumer group performance across the transaction processing pipeline, implementing partition-aware batching and back-pressure mechanisms that maintained sub-100ms consumer lag under peak booking volumes. Profiled JVM allocation rates on hot-path consumers using async-profiler, identified and eliminated major allocation sites in the serialization layer ? reducing GC pressure by ~60% and achieving consistent processing latency during peak-hour traffic spikes. 
  • Drove technology selection and architectural decisions across the platform engineering team, including the evaluation and adoption of Apache Kafka over legacy JMS messaging ? structuring the evaluation as a mentoring exercise for junior engineers (throughput benchmarks, failure recovery semantics, schema evolution trade-offs).
Java 8 async-profiler Spring Boot Spring Kafka Apache Kafka Hadoop Azure Kubernetes Docker Helm Jenkins Git
Lufthansa Airplus Servicekarten GmbH
1 year 6 months
2018-01 - 2019-06

Traveler Information System (RIS)

Senior Software Engineer Java 8 Spring boot Multithreading ...
Senior Software Engineer
Architected and delivered mission-critical components of the RI-Platform (Traveler information system), a centralized real-time data platform serving millions of daily passengers across thousands of trains, processing hundreds of millions of events daily with 99.9% availability.
  • Architected and owned event-driven microservices within a ~100-microservice ecosystem, processing 60M daily tracking incidents from signaling systems, GPS, and IoT sensors to deliver real-time train positioning, delay forecasts, and platform assignments to 800+ stations. Led the technical design of the ingestion layer, defining latency budgets, partitioning strategies, and data contracts across upstream signal providers and downstream consumer services.
  • Built high-throughput Kafka Streams pipelines achieving sub-second data propagation to 6,600+ display devices. Profiled and optimized JVM performance across latency-critical consumer services ? tuned G1GC pause targets, heap generation sizing, and thread-to-core affinity via JNI ? reducing p99 processing latency by ~40% and eliminating GC-induced stalls during peak traffic.
  • Replaced Jackson-based JSON serialization on high-throughput Kafka event streams with optimized binary encoding, reducing per-message serialization overhead by ~75% and eliminating allocation pressure on the critical ingestion path. Evaluated SBE and FlatBuffers against schema evolution requirements and downstream consumer compatibility, selecting the approach that balanced latency gains with the team's operational constraints.
  • Observability: Implemented comprehensive monitoring (Prometheus, Grafana, Elastic Stack) for real-time system health across distributed microservices, supporting the platform's "you build it, you run it" DevOps culture within a 110-engineer, 13-scrum-team organization
Java 8 Spring boot Multithreading Low latency GC tuning Python Apache Kafka Kafka Streams Apache NiFi Hadoop/HDFS MongoDB Docker Kubernetes AWS Elastic Stack Prometheus Grafana Jenkins
Deutsche Bahn
2 years 8 months
2015-03 - 2017-10

Big Data infrastructure for the Corporate and Investment Bank

Software Development Engineer Java Spring Boot JMS ...
Software Development Engineer

Contributed to the architecture and delivery of a mission-critical Big Data infrastructure for the Corporate and Investment Bank, enabling real-time counterparty exposure tracking, risk aggregation, and regulatory reporting across Deutsche Bank's global trading and banking operations.

  • Contributed to the design and implementation of an enterprise data lake covering Liquidity, Credit Risk, Collateral Management, and Counterparty Exposure?consolidating risk data from siloed legacy systems into a unified platform. Supported the bank's strategic goal of creating a single source of truth for risk data aggregation across multiple databases and multiple business divisions, directly addressing regulatory requirements.
  • Developed high-throughput Java/Spring services exposing aggregated risk and exposure data to downstream consumers including Finance, Risk Management, and Regulatory Reporting systems
  • Collaborated on ETL solutions consolidating Balance Sheet and P&L data across business divisions, powering management and regulatory reporting. Platform enabled 30%+ reduction in manual reconciliation effort and accelerated time-to-report for stress testing and capital adequacy submissions.
  • Contributed to the bank's operational efficiency program through automation of data workflows, reduction of manual processes, and standardization of data governance practices across the Corporate Bank and Investment Bank divisions.

Java Spring Boot JMS Apache Storm Apache Spark Hadoop/HDFS Hive MarkLogic Multithreading RESTful Web Services Git Jenkins CI/CD Scrum/Agile
Deutsche Bank
Frankfurt and London

Aus- und Weiterbildung

Aus- und Weiterbildung

1 year 6 months
2013-10 - 2015-03

Information Systems

MSc Computer Science (1.6), Technical University Munich, Germany
MSc Computer Science (1.6)
Technical University Munich, Germany

Position

Position

Senior Software Developer

Kompetenzen

Kompetenzen

Top-Skills

Java Spring Boot Microservices C++ Rust

Produkte / Standards / Erfahrungen / Methoden

Profile

Senior Software Engineer with 10+ years of experience across finance and payments, transport and logistics, and proprietary trading ? specializing in latency-critical distributed systems and event-driven microservice architectures in Java, C++ and Rust. Architected high-throughput platforms spanning real-time risk aggregation, large-scale data systems (180M events/day), and mission-critical payment infrastructure serving 55,000+ enterprise clients. As founder-engineer, designed and delivered production trading systems end-to-end: sub-100?s tick-to-trade engines, a microservice-based Spring Boot platform on a Kafka backbone processing 10,000 events/second at sub-500ms p99. Technical leader who drives architectural decisions, establishes performance engineering culture, and scales teams through structured mentoring.


Skills:

System & Architecture:

  • Low-latency systems
  • Event-driven microservices
  • Lock-free & zeroallocation pipelines
  • Real-time data processing
  • Distributed systems
  • JVM performance tuning
  • Low-level programming


Data & Messaging:

  • Apache Kafka
  • Redis
  • PostgreSQL
  • TimescaleDB
  • Apache Avro
  • MongoDB


Frameworks & Software:

  • Spring Boot
  • Spring Kafka
  • Spring Cloud Gateway
  • Kafka Streams


DevOps:

  • AWS
  • Azure
  • Docker
  • Kubernetes
  • Helm
  • CI/CD
  • Ansible
  • Maven
  • Gradle

Programmiersprachen

java
Experte
C++
Fortgeschritten
Rust
Fortgeschritten

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