Boris Petrov
Fractional senior frontend engineer
Amazon·
Google→independentAreas of focus
Complex state modeling
Beyond fetch-and-render: multi-step async flows, user interactions, validation logic, error/loading states, caching – all colliding. Modeling the intersections explicitly and extensibly.
Design feasibility and tradeoffs
Auditing designs for missing states, impossible interactions, patterns that won't survive real data. Finding the 80/20 between design fidelity and engineering cost.
AI workflow UX
Interfaces where AI generates content humans review and approve – soliciting suggestions, handling async generation, merging results into existing work.
Selected client work
Radical Tempo
·15 monthsAI-augmented video publishing platform
- Second engineer hired — zero to early-access launch
- Multi-phase pipeline state: transcoding, AI generation, rendering, each with its own progress and failure modes
- Layered data fetching: server components, React Query caching, Supabase Realtime
- Cross-platform publish form: one view serving 8 platform types with per-platform validation and field constraints
- Design collaboration on AI-augmented workflows with few established patterns
California Pizza Kitchen
·22 monthsRestaurant chain website and ordering system
- Led team of 3 across frontend, CMS, and backend
- Inherited and stabilized a codebase left broken by the previous agency
- SEO boost via programmatically generated location pages (100+) and CMS-powered menu pages
- System of smart redirects/deep-links to ordering platform, preserving loyalty session
- 25% homepage load time reduction; CMS storage and bandwidth optimization
- WCAG accessibility and GDPR/CCPA cookie compliance
Navii
·1 monthAI assistant for career development
- Brought on for urgent stabilization of agent-built frontend weeks before launch
- Issues with React component lifecycle, global state management, caching
- Audited, advised, then implemented highest-impact fixes under tight deadline
- Laid guardrails for post-launch changes
Also worked with
Lasso Labs
Rising Stars AI
SpeakEasy
Engineered Tax Services
Subcity
Mirror
Some client work is under NDA or behind logins.
When teams bring me in
Inflection point
Approaching a launch, fundraise, or growth spike and need extra muscle to get it over the line.
Expertise gap
Need senior frontend but not sure it's a full-time role – or not sure yet how long the need lasts.
Parallel workstream
Core team is heads-down on roadmap while a new initiative (experimental, time-sensitive) needs to progress.
Testimonials
“He brought a level of craft to everything he built… had a strong partnership with our designer, which made a huge difference in what we were able to ship… reliable as hell when it comes to hitting deadlines.”
Ravi Kolluri
Cofounder & CTO, Radical Tempo
“Boris’s super power is that he looks beyond the technical and grasps the business objective… It’s rare to find a technologist who can push and pull at a business level to deliver results in the form of revenue.”
David Harris
VP of Digital, California Pizza Kitchen
“He always goes above and beyond to assess the clients’ needs and flag any potential roadblocks early on… Boris excels as a team lead and manager, ensuring that the team is well-equipped for any project and capable of overcoming any challenge.”
Alexz Graves
Sr. Creative Producer, Planetary
“…a great problem solver… He presents his way as an option to consider and seeks input from others on pros and cons… He spends time trying to understand the problem and having empathy for the user.”
Ajoy Bhambani
Founder, Rising Stars AI
“I’ve worked with Boris on multiple occasions with different budget, timing, and expertise requirements, and every time, Boris has been able to deliver high quality work… His communication skills regarding estimates, technical tradeoffs, and user requirements are top notch.”
Molly Nacey
Fractional CTO/CPO
“…holds a very high bar for quality… has earned trust with the team as someone who can work independently with PMs, UX and TPMs to figure out the goals, requirements, risks and schedule for a project and then successfully execute.”
Chris Bee
Engineering Manager, ex-Amazon/Zillow/Uber