Vetted Unit Testing Professionals

“Significant contributor/maintainer to an open-source JavaScript event-tracking client SDK, owning API consistency/backward compatibility, high-load batching and retry/backoff improvements, and test/CI + documentation upgrades. Diagnosed production-like issues (missing events under load) via reproduction and logging, then reduced GC pressure and improved predictability with a ring-buffer-based batching redesign while actively triaging issues and reviewing PRs.”

“Full-stack engineer with production experience building Java 17 Spring Boot microservices for high-traffic systems at Verizon and on a JPMC payments platform (funds transfer/validation using ISO 20022), plus modern React/TypeScript dashboards for ops and analytics. Demonstrates strong scalability and reliability chops (Kafka event-driven pipelines, Redis caching, clustering, BullMQ background jobs) and has built real-time apps end-to-end with secure JWT refresh-token auth and Socket.io performance tuning.”

“Backend/DevOps-leaning engineer with trading/financial systems experience (AIG), focused on reliability: built Python automated test suites to ~95% coverage and integrated them into CI/CD. Has hands-on Kubernetes microservices deployment with GitOps (ArgoCD), plus experience supporting cloud-to-on-prem migrations and building real-time streaming pipelines resilient to spikes and data loss.”

“Built production LLM/RAG platforms for financial services to enable natural-language Q&A over large policy/compliance document sets stored in Snowflake and SharePoint. Strong in MLOps and orchestration (Airflow, ADF, Step Functions, MLflow) and in solving real production issues like stale embeddings and model performance, including an incremental Snowflake Streams sync that cut processing time from hours to minutes.”

“Backend/platform engineer with hands-on ownership of high-stakes data migrations in regulated domains (core banking and insurance), including a Python ETL framework that migrated 100,000+ customer records within a cutover window. Strong DevOps/GitOps background deploying Python and Spring Boot microservices to Kubernetes with Helm and ArgoCD, plus real-time Kafka transaction streaming for fraud/analytics with reliability patterns (DLQs, retries, partition tuning).”

“Customer-facing software engineer who builds configurable, extensible solutions under vague requirements (e.g., a bin-packing-style resource allocation feature) and iterates via frequent sandbox deployments and customer testing. Has hands-on experience integrating multiple shipping APIs, navigating outdated/unclear documentation, and resolving production issues quickly through log-driven debugging and safe rollback procedures.”

“ML/AI engineer with defense and commercial analytics experience: deployed a real-time aerial object detection system at Dynetics (YOLOv5 + TorchServe in Docker on AWS EC2) with drift-triggered retraining and 99.5% uptime, tackling ambiguous targets and weather degradation. Previously at Fractal Analytics, built and explained a churn prediction model for marketing stakeholders using SHAP and delivered it via a Flask API into dashboards, driving a reported 22% attrition reduction.”

“ML/NLP practitioner focused on financial-services document intelligence and compliance workflows—built an end-to-end pipeline to classify documents and extract financial entities from loan applications, emails, and statements stored in S3/internal databases. Strong in entity resolution/record linkage and in productionizing pipelines with GitHub Actions CI/CD, testing, data validation, and Docker, plus semantic search using OpenAI embeddings and a vector database.”

“NLP/ML practitioner who built an explainable, clinician-aligned system to detect cognitive decline (Alzheimer’s/stroke-related) from audio responses, achieving 97% accuracy on only a few hundred data points. Also has experience with healthcare claims entity resolution and prototyped a word2vec-based patent search vector database in Elasticsearch, with strong emphasis on testing, interpretability, and scalable Python data workflows.”

“ML/NLP practitioner with banking experience (M&T Bank) who has built a GPT-4 RAG system using LangChain and Pinecone to connect unstructured customer data with internal knowledge bases, improving accuracy and reducing manual lookup time by 50%+. Strong in entity resolution and productionizing scalable Python data workflows, including major performance wins by migrating bottleneck joins from Pandas to Dask.”

“Backend-leaning full-stack engineer from ADP’s Global View team who owned major backend components of an enterprise payroll dashboard, including a fault-tolerant multi-step payroll processing workflow and error visibility features. Strong in Java/Spring Boot + PostgreSQL schema design and Redis caching, with additional production experience in Python services (JWT, testing, SonarQube) and AWS deployments via Terraform/Jenkins with autoscaling.”

“Backend/full-stack engineer with finance domain experience (State Street) who built and shipped a Kafka-based real-time trade validation system handling 50k+ trades/sec and cut latency by 42%. Also delivered real-time React dashboards (Redux Toolkit/React Query/WebSockets) and operates AWS EKS microservices with GitOps/ArgoCD; has built a FastAPI + LangChain/GPT-4 intelligent document processing service with JWT/RBAC.”

“QA/project leader with ~19 years experience running high-profile, multi-million-dollar software initiatives and driving quality through disciplined milestone gates (Alpha/Beta/FC/GM), regression planning, and weekly bug scrubs. JIRA-centric practitioner (Zephyr/Confluence) who partners closely with engineering, automation, documentation, marketing, and sustaining teams—including offshore collaboration—to unblock testers and improve diagnostics for difficult issues like memory leaks.”

“QA/automation engineer with hands-on experience spanning web UI automation (Cypress/JavaScript) and hardware/firmware validation (BIOS/BMC, FPGA). Has delivered high-impact reliability and throughput improvements in server/HPC environments, including automation that enabled booting across ~250 servers and requirement clarification that unblocked firmware work for ~550 servers.”

“Software engineer with experience at Freddie Mac shipping a production workflow tracking and daily summary dashboard that replaced spreadsheet/email-based operational processes. Worked across frontend (React/JavaScript), backend (Java), Oracle relational data, and CI/CD, with emphasis on stakeholder collaboration and post-deploy testing/monitoring/performance tuning.”

“Backend/AI engineer who has built production Spring Boot APIs on AWS (JWT auth, Redis/MySQL) and solved a real-world silent data integrity issue by implementing idempotency keys plus DB constraints/transactions. Also shipped an LLM-based document Q&A feature using a RAG pipeline with evaluation + human review, and designed multi-step agent workflows with verification, retries, and escalation guardrails.”

“Full-stack product engineer who has shipped polished customer-facing experiences across iOS (SwiftUI), web (Next.js/React/TypeScript), and Python backends. Built systems ranging from an escalating smart-reminder engine to a sub-200ms search UI over 6M+ court records, and owned AWS production operations including resolving a real DB-connection-exhaustion incident with scaling and architectural hardening.”

“Game/tools-focused QA professional with experience at Playable Worlds, Disney, and Metaplace, emphasizing CI-driven quality (Jenkins PR gating, unit tests, Slack/JIRA visibility) in live production environments. Has hands-on defect isolation experience using developer tools to diagnose hard-to-repro player issues and improve turnaround by providing reliable repro steps and clear QA workflows.”

“Full-stack engineer with ~3.5 years of Java Spring Boot and React experience who built an end-to-end banking transaction platform using microservices, Kafka streaming, AWS RDS, and Dockerized CI/CD. Demonstrates strong performance and reliability engineering (async processing, DLQ/retries, idempotency, caching) plus secure cloud deployment practices; has also worked across banking, healthcare, and insurance domains.”

“Data engineer with Charter Communications experience modernizing large-scale AWS data lake pipelines: ingesting S3 data, validating against legacy systems, transforming with PySpark/Spark SQL, and serving via Iceberg/Delta tables. Worked at 50M–300M record scale, delivered >99.5% data match, and built monitoring/alerting (CloudWatch/SNS) plus retry orchestration (Step Functions) and data quality gates (Great Expectations).”

“Backend engineer who built an AI-driven "Smart Feedback Analyzer" API (Flask → FastAPI) that processes user feedback with NLP (Hugging Face + OpenAI) and returns structured insights. Demonstrates strong production-minded architecture: stateless services, Cloud Run + Docker deployment, Redis/Celery background processing, and Postgres/SQLAlchemy performance tuning (EXPLAIN ANALYZE, indexing, N+1 fixes), plus multi-tenant data isolation via JWT/API-key derived tenant IDs.”

“Full-stack engineer with hands-on production experience building real-time customer-facing features (order tracking + push notifications) across React/React Native and Node/Spring Boot with Postgres/MySQL. Demonstrates strong reliability patterns (transactional outbox, background workers, idempotent webhook ingestion) and has deployed/operated systems on AWS (ECS/Fargate/ALB, CloudWatch, CodePipeline) with structured observability and environment separation.”

“Full-stack engineer with hands-on ownership of real-time, Kafka-driven systems in production, spanning React/TypeScript frontends, Spring Boot/Node backends, and AWS (EKS/ECS/EC2) operations. Notable for modernizing legacy batch workflows into event-driven architectures with measurable impact (35% faster risk calculations, 30% better accuracy) and scaling to 2x volume using reliability patterns like idempotency, retries, and staged rollouts.”

Hleb Rahoisha

Screened

Senior Unity/C# Developer specializing in mobile and VR games

Warsaw, Poland7y exp

“Unity gameplay engineer with hands-on experience spanning AI behavior-tree architecture (Behavior Designer), authoritative multiplayer networking (Photon/Mirror), and aggressive VR (Meta Quest) optimization. Built designer-friendly tooling (Excel-driven balancing, prefab automation bridging Marvelous Designer/Blender/Unity) and has experience mentoring juniors within an entity/HMVC-based architecture at Playtica.”