Most companies want to ship AI features. Few have engineers who can ship them without breaking production.

I'm Konstantin — a senior backend and cloud engineer with 20+ years building distributed systems, APIs, and infrastructure for B2B SaaS / fintech / e-commerce. Over the last 3 years I've been specifically focused on integrating LLMs into existing backends: RAG pipelines, agent workflows, function-calling, evaluation harnesses, observability, cost control, and the boring-but-critical work of making AI features reliable enough to put in front of paying customers.

Things I'm good at:

• Designing RAG and agent systems that don't fall over under real load

• Building eval pipelines so you actually know when your prompts or models regress

• Cost-controlling LLM workloads (caching, routing, fallback, batching)

• Cloud architecture on AWS / K8s — migrations, modernization, cost optimization

• Working with small senior teams as an embedded staff/principal engineer

How I work: fractional engagements, 1–2 days per week, remote across EU and US time zones. I run focused 4-week sprints with fixed scope and fixed fee, or month-to-month retainers for longer engagements. I don't take on more than 2 active clients at a time.

Past work includes scaling a payments API from 50 req/s to 4k req/s and shipping a RAG-backed support assistant for a Series B SaaS, handling 200k queries/month.

If your team is trying to put AI into production and wants a senior pair of hands who's done it before — DM me here or book a meeting. Currently booking engagements for Q3 2026.