Offer summary

Qualifications:

5+ years of experience in Python development, with expertise in async programming and performance profiling., Hands-on experience building real-time speech recognition (ASR), text-to-speech (TTS), and streaming audio products., Familiarity with fine-tuning, prompt design, and evaluation of large language models (LLMs) using frameworks like LangChain or LlamaIndex., Knowledge of systems and MLOps practices, including containerization, GPU scheduling, and cloud infrastructure..

Key responsibilities:

Design and implement real-time speech pipelines (ASR → LLM → TTS) meeting latency and quality standards.

Evaluate, fine-tune, and integrate state-of-the-art speech and language models into production.

Optimize inference performance through techniques like quantization and hardware-aware compilation.

Develop and maintain scalable APIs and microservices, ensuring observability and autoscaling.

Job description

Synthflow AI is a no-code platform for deploying voice AI agents that automate phone calls across contact center operations and business process outsourcing (BPO) at scale. We help mid-market and enterprise companies manage routine calls to save teams time and resources.

Our agents have already delivered measurable impact:

Over 5 million hours of contact center operations saved
35% more calls answered compared to non-AI operators
45 million calls handled with a 99.9% uptime

Backed by Accel, Atlantic Labs, and Singular and trusted by over 1,000 customers, our growth leads an industry shift toward sophisticated and accessible conversational AI.

The Role

We are looking for a hands‑on ML Engineer who lives at the intersection of TTS, STT and large language models. You will design and ship new low‑latency voice capabilities, working closely with product, research and infrastructure teams to push the boundaries of natural, multilingual conversation.

What You’ll Do

Architect & implement real‑time speech pipelines (ASR → LLM → TTS) that meet stringent latency and quality targets.
Evaluate and fine‑tune state‑of‑the‑art ASR, LLM and TTS models—both commercial and open‑source—and integrate the best performers into production.
Optimise inference through quantisation, distillation, hardware‑aware graph compilation and reinforcement‑learning‑based tuning.
Expose scalable APIs & micro‑services with Python/FastAPI, gRPC or WebSocket streaming, backed by robust observability and autoscaling.
Own deployment across cloud and on‑prem environments, collaborating on containerisation (Docker), orchestration (Kubernetes) and CI/CD workflows.
Stay ahead of the curve by tracking research, running experiments and sharing learnings with the broader team.

What we’re looking for

Python Engineering: 5+ years writing production‑grade, well‑tested Python; deep familiarity with async, typing and performance profiling
Speech / Audio: Hands‑on experience building real‑time ASR, TTS, voice chat or streaming audio products
LLM Tooling: Fine‑tuning, prompt design, evaluation, retrieval‑augmented generation; familiarity with frameworks such as Openpipe/ART, LangChain, LlamaIndex or similar
Systems & MLOps: Containerisation, GPU scheduling, observability, DevOps on GCP or AWS; infrastructure‑as‑code principles
API Design: Building and maintaining high‑throughput REST/gRPC/FastAPI services; securing and monitoring them in production

Bonus Points

Model compression expertise (quantisation, pruning, ONNX/TensorRT)
Knowledge of audio and acoustics
Experience with reinforcement‑learning‑from‑human‑feedback (RLHF) or direct preference optimisation
Contributions to open‑source ML/speech projects (share your GitHub!)
Familiarity with GPU inference servers (Triton, KServe) or distributed compute frameworks (Ray)

Founded in Berlin in 2023 by serial entrepreneurs Albert Astabatsyan, Hakob Astabatsyan, and Sassun Mirzakhan-Saky, Synthflow AI democratizes access to advanced voice AI with a no-code platform that lets enterprises easily create, deploy and scale natural-sounding, cost-effective voice agents tailored to their business needs.

Required profile