Senior Backend Engineer - Speech Platform
Summary
Backend owner for Rezo.ai's speech team: build large-scale audio data pipelines, real-time low-latency inference services (streaming, mid-utterance interruption), GPU training infrastructure, and integrate speech services into the existing Java platform and telephony stack. Core stack: Java, Python, Docker/Kubernetes, cloud, streaming APIs.
- Build the audio data pipeline: mine our call archive, transcode, resample, segment, deduplicate and quality-filter at scale
- Build and operate real-time inference services with hard latency targets, including streaming, cancellation and mid-utterance interruption
- Integrate speech services into our existing Java-based platform and telephony infrastructure
- Instrument the full latency budget end to end and find where the milliseconds go
- Stand up training infrastructure — GPU scheduling, checkpointing, experiment tracking, reproducibility
- Own compute cost and concurrency economics: how many simultaneous calls per GPU, and how to improve it
- Support on-premise deployment for clients who can't send data outside their network
Requirements
- 3–4 years building and operating production backend systems
- Strong Java — you've owned services in production, not just contributed to them
- Working Python — enough to build data pipelines and integrate with ML tooling
- Real-time or low-latency systems experience: streaming APIs, WebSocket or gRPC streaming, concurrency, backpressure
- Data pipelines at scale (Airflow, Dagster, Spark or equivalent)
- Docker and Kubernetes in production
- Cloud infrastructure (AWS/GCP/Azure)
- Comfortable debugging performance: profiling, latency percentiles, throughput under load
- Serving ML models in production (Triton, vLLM, TorchServe)
- Audio tooling — ffmpeg, sox, codecs, resampling
- Telephony — SIP, Asterisk/FreeSWITCH, media servers, narrowband codecs
- MLOps tooling: MLflow, Weights & Biases, DVC
- GPU-aware infrastructure work