Harsis YadavSenior Full-Stack Engineer · Amsterdam
I build SaaS that survives production.
I'm Harsis. I build secure multi-tenant platforms and AI-powered workflows, owning everything from the PostgreSQL schema to the interface and the cloud it runs on.
Results that held up in production.
387 → 7 ms
Hot read query over 6.6M rows
Roughly 55× faster for that query on a multi-tenant PostgreSQL platform.
8 → 1
SQL statements per access check
Serial per-request authorization queries collapsed into a single statement.
600+ s
Removed from an ML pipeline run
Through in-memory caching and result reuse with the data science team.
Measured on specific queries and pipelines, not whole-platform speedups.
Selected work, end to end.
ACE RegTech · 2026 – present
Rebuilding a core module of a multi-tenant AI SaaS platform
Replacing a legacy module on a multi-tenant compliance SaaS platform with a faster, safer, AI-assisted workflow, without breaking the links customers already relied on.
- hot read query across 6.6M rows
- 387 → 7 ms
- hot read query across 6.6M rows
- serial SQL access checks per request
- 8 → 1
- serial SQL access checks per request
Forward Football · 2024 – 2025
Scaling an ML-driven football analytics platform
Turning data science models into a multi-tenant product: faster pipelines, secure team-level data access, and a dashboard coaches and analysts could actually use.
- removed from ML pipeline runtime
- 600+ s
- removed from ML pipeline runtime
- interactive charts and filters in the dashboard
- 30+
- interactive charts and filters in the dashboard
Side projects
Stocktrix, a 3D lab, and open source.
FinBERT sentiment analysis over stock news, a React Three Fiber playground, and contributions to shadcn/ui and coala.
01
Architecture
Model data and trust boundaries first: tenancy, permissions, failure modes.
02
Delivery
Small, reversible steps behind feature flags; migrations that run both ways.
03
Verification
Query plans, benchmarks, and end-to-end tests, not just green CI.
04
Operation
Observability, safe rollouts, and fixing what users actually hit.
Engineering beyond the demo.
🐘 The PostgreSQL NULL Trap: When a Security Check Isn't Really a Security Check
How NULL semantics can quietly weaken tenant isolation, and how to make PostgreSQL security checks fail closed.
⚽️ Outdoor tracking with Ultra-Wideband (UWB) networks
How to track location offline and without GPS?
💸 Stocktrix - Smarter Way to Read Financial News
How I built Stocktrix, a FastAPI and Next.js app that summarizes financial news and predicts stock sentiment.
From network switches to SaaS platforms.
Eight years across C/C++ networking at Arista and HPE and modern SaaS and AI product work. Outside work I write, make videos, and get taken on "mandatory fun" trips by my wife.
- 2026 – presentACE RegTech · Senior Full-Stack Engineer
- 2024 – 2025Forward Football · Lead Full-Stack Developer
- 2021 – 2024Arista Networks · Software Engineer
- 2018 – 2021HPE Aruba · Software Engineer II
A product problem, or an engineering role?
Tell me what you're building and where it hurts.