# Diffco

> Diffco is a Silicon Valley AI engineering and custom software development firm. Since 2008 we have built production-grade web, mobile, SaaS and AI products for startups and mid-size enterprises — senior US-led engineers accelerated by AI tooling, with a delivery methodology built around getting AI to production.

Diffco US Inc. is headquartered at 333 W San Carlos St, Suite 600, San Jose, CA 95110, and operates worldwide. Team of engineers, designers and product managers. Leadership: Vadim Peskov (CEO & Co-founder), Eugene Nasonov (CTO & Co-founder), Paul Shpin (VP of Engineering).

What we do: custom software development with AI; AI/ML engineering (RAG, LLM applications, computer vision, fine-tuning); agentic AI engineering (custom agents, copilots, multi-agent systems); AI-native software engineering for web, mobile and SaaS products; AI-driven product discovery; staff augmentation with senior engineers; web and mobile development; and consulting on AI-native development practices (delivery methodology, agentic workflows, tooling).

Industries include SaaS, healthcare, fintech, manufacturing and industrial IoT, real estate, education, retail and hospitality.

How engagements start: a free architecture review call, then typically a paid two-week Discovery Sprint that ends in a scoped plan, architecture and cost estimate. Delivery models: end-to-end product builds, embedded engineering teams, engineering takeovers and rescues (including taking vibe-coded prototypes to production), and ongoing support.

Credentials: Clutch Top AI Development Company; DesignRush Top 10 Software Developers; GoodFirms Top AI Developers in California; Capterra Top Staff Augmentation Company. 18+ years, 1,450+ products shipped, 500+ satisfied clients, 99% on-time delivery, and 38+ AI products and agents built or put into production in the last year.

Products we developed are used by American Express, Whole Foods Market, Nokia, Starbucks, Mars, Hilton and ChemTreat.

Contact: mail@diffco.us · +1 (415) 655-1002 · Book a call with the Diffco: https://diffco.us/contacts/

## Services

- [All services](https://diffco.us/services/): Index of Diffco's engineering services.
- [AI & ML Development](https://diffco.us/services/ai-development/): Production-ready AI, ML, RAG and computer vision systems, from data pipeline to deployed model.
- [AI Agents Development](https://diffco.us/services/agentic-ai-engineering/): Custom AI agents, copilots and multi-agent systems with evals, guardrails and observability; SOC 2-aligned engagement practices, HIPAA- and GDPR-aware delivery.
- [AI-Driven Product Discovery](https://diffco.us/services/ai-driven-product-discovery/): Two-week discovery sprint that answers "should we build this, and what will it cost to run?" before committing a budget.
- [AI-Native Transformation](https://diffco.us/services/ai-native-transformation/): Making an engineering team AI-native without breaking what works: a fixed three-week Discovery sprint that maps what is safe to transform, what needs prep first and what stays off-limits, with six deliverables the client keeps (delivery pipeline map, codebase readiness, context and spec audit, transformation roadmap, cost and effort model, go / reshape / no-go memo).
- [Web Development](https://diffco.us/services/web-development/): Custom web applications and SaaS products, front-end (React, Next.js, design systems) and back-end (APIs, databases, cloud infrastructure); typical timelines — discovery 1–2 weeks, proof of concept 2–4 weeks, MVP 6–12 weeks.
- [Front-end Development](https://diffco.us/services/front-end-development-services/): Front-end engineering for web and mobile products by senior engineers: React, Next.js, Angular, Vue.js, Electron and TypeScript, design systems, accessibility (WCAG 2.1 AA), admin panels and third-party integrations.
- [React Development](https://diffco.us/services/react-development/): React and TypeScript front ends by senior engineers: new products and dashboards, design systems, performance and accessibility (WCAG 2.1 AA) fixes, React 19 and Create React App migrations, and the interfaces of AI features.
- [Forward Deployed Engineers](https://diffco.us/services/forward-deployed-engineer/): A senior AI engineer embedded in your team — your standups, repos and systems — shipping AI agents and features into production, with an architect, a specialist bench and 100+ AI agents per engineer behind them; starts with a one-to-two-week scoping sprint.
- [Fractional AI Partner](https://diffco.us/services/fractional-ai-partner/): Part-time AI leadership for mid-size companies from Diffco's CTO and senior AI architects: a 1–2 week AI assessment with a ranked use-case roadmap, then ongoing AI leadership, governance and vendor decisions, with a senior team to build the agent layer on the systems you already run when the plan calls for it.
- [Mobile Development](https://diffco.us/services/mobile-development/): Native iOS and Android and cross-platform apps.
- [Team Augmentation](https://diffco.us/services/team-augmentation/): Senior engineers embedded in your team, based in the US, Europe and Latin America, with a 3+ month minimum engagement.

## Solutions

- [All solutions](https://diffco.us/solutions/): Index of Diffco's solution areas.
- [Custom Software Development](https://diffco.us/solutions/custom-software-development/): End-to-end builds for startups and businesses, from MVP to scale.
- [AI-Driven Software](https://diffco.us/solutions/ai-driven-software/): Products where AI is the engine — recommendation, automation, conversational and vision systems.
- [Enterprise Applications](https://diffco.us/solutions/enterprise-applications-development/): Internal tools, ERPs, integrations and modernization for mid-size enterprises.
- [Healthcare Software Development](https://diffco.us/solutions/custom-healthcare-software-development-company/): HIPAA-aware platforms for providers, veterinary practices and health-tech startups.
- [MVP Development](https://diffco.us/solutions/mvp-development/): Production-ready MVPs built for real users, fast feedback and every release after.
- [Vibe Code Rescue](https://diffco.us/solutions/vibe-code-rescue/): Taking Lovable, Bolt, Replit and Cursor prototypes to production: triage, then stabilize, harden, move off the builder or rebuild, with senior engineers and a free 30-minute code review.
- [Claude Code Development](https://diffco.us/solutions/claude-code-development/): Claude Code set up for engineering teams and products built on it: a plan, rules and an automatic check on every change in your repo, senior engineers directing 100+ agents each, and a person signing off before release. A two-week setup sprint or a full build.
- [Fintech Software Development](https://diffco.us/solutions/fintech-software-development/): Banking and lending platforms, payments and marketplaces, fund accounting and ERP, expense and receipt AI, and agentic workflows for regulated environments, built with idempotent money paths, enforced access control and audit trails; SOC 2-aligned practices.
- [Fractional CTO Services](https://diffco.us/solutions/fractional-cto/): Fractional CTO leadership from Diffco's CTO and senior architects (architecture, roadmap, vendor and agency oversight, engineering hiring, investor and board support, AI strategy), starting with a fixed-price assessment, with a senior engineering team available when the plan calls for building.

## Case studies

- [All case studies](https://diffco.us/cases/): 70+ projects across AI, SaaS, mobile, fintech, healthcare and industrial IoT.
- [Maze](https://diffco.us/cases/maze/): The AI that runs AI-moderated user-research interviews, plus the real-time participant interface — built in WebGL inside Maze's monorepo and live in production, running interviews in 20 languages.
- [Happier Meditation](https://diffco.us/cases/happier/): Engineering takeover of a consumer meditation app (iOS, Android, Rails) the month its in-house team left — uninterrupted operation of a 4.8★, 143K-review App Store product through a major organizational transition.
- [Instreamatic](https://diffco.us/cases/instreamatic/): The iOS and Android delivery layer for an interactive audio and video advertising platform — native SDK components and adaptive HLS streaming for AI-driven, two-way ad conversations.
- [RedTrack](https://diffco.us/cases/redtrack/): AI-native engineering for an ad-tracking platform whose productivity curve had flattened despite Claude Code already running in CI — Discovery found the bottleneck was context rather than code generation, and Diffco installed the practice around it.
- [Vitality Access](https://diffco.us/cases/vitality-access/): Medical-tourism marketplace and staff admin built in eight weeks at under half the first estimate — Next.js, Supabase, Stripe.
- [RepoScore](https://diffco.us/cases/reposcore/): An internal mobile app and web portal for HNS Recovery that unify repossession, GPS and fuel data from three separate systems into one live per-agent performance score.
- [SaveIT](https://diffco.us/cases/saveit/): Ongoing engineering for an AI receipt and expense platform — back-end and mobile app rebuild, receipt recognition moved onto a modern AI model stack, hardened security and integrations, and a new website.
- [Gitcha](https://diffco.us/cases/gitcha/): Embedded engineering team behind a real-estate platform's Version 2 — React/Node refactor, AWS and CI/CD.
- [Good2Go](https://diffco.us/cases/good2go/): Core platform development and AWS/Azure migration for a patented keyless-access startup.

## Insights

- [Blog](https://diffco.us/blog/): Practitioner writing on production AI engineering by Diffco's team.
- [Better models don't mean better software: Vadim Peskov on Pale Blue Nexus](https://diffco.us/blog/better-models-dont-mean-better-software-vadim-peskov-on-pale-blue-nexus/)
- [Why you still need developers in 2026 — and why vibe-coding everything is a trap](https://diffco.us/blog/why-you-still-need-developers-in-2026-and-why-vibe-coding-everything-is-a-trap/)
- [Vibe-code rescue: taking a Lovable or Bolt prototype to production](https://diffco.us/blog/vibecode-rescue-taking-a-lovable-or-bolt-prototype-to-production/)
- [AI-native vs AI-assist development: two different jobs, often confused](https://diffco.us/blog/ai-native-vs-ai-assist-development-two-different-jobs-often-confused/)
- [Multi-agent system architecture: a teardown of how we built a customer support agent](https://diffco.us/blog/multi-agent-system-architecture-how-we-built-a-customer-support-agent/)
- [7 mistakes that kill RAG performance in production](https://diffco.us/blog/7-mistakes-that-kill-rag-performance-in-production/)
- [MLOps for LLM products in 2026: observability, evals and cost control](https://diffco.us/blog/mlops-for-llm-products-in-2026-observability-evals-and-cost-control/)
- [Self-hosted vs API-based LLMs: the 2026 cost and control trade-off](https://diffco.us/blog/self-hosted-vs-api-based-llms-the-2026-cost-and-control-tradeoff/)
- [AI agents vs copilots vs automations: a C-level decision framework](https://diffco.us/blog/ai-agents-vs-copilots-vs-automations-a-c-level-decision-framework-for-2026/)
- [AI in fintech: building secure agentic workflows for regulated environments](https://diffco.us/blog/ai-in-fintech-building-secure-agentic-workflows-for-regulated-environments/)
- [How to choose an AI development partner in 2026](https://diffco.us/blog/how-to-choose-an-ai-development-partner-in-2026/)

## Company

- [About Diffco](https://diffco.us/about-us/): Leadership, history since 2008, delivery methodology and client testimonials.
- [AI SDLC methodology](https://diffco.us/ai-sdlc-methodology/): How Diffco builds software: senior engineers decide what to build, 100+ AI agents build it inside a living plan with automatic checks, and a person signs off on every release.
- [Clients](https://diffco.us/clients/): Client logos and testimonials, including ChemTreat, Nokia Care, FlashGrid, Instreamatic, RedTrack, Maze, Happier, Good2Go, Gitcha, Food Rocket, Latoken, NanaWall, Questroom, TabsApp and Vitality Access.
- [Contact](https://diffco.us/contacts/): Request a quote or book a call.
- [Careers](https://diffco.us/career/): Open roles.
- [LinkedIn](https://www.linkedin.com/company/diffco): Company LinkedIn page.
- [X](https://x.com/Diffco_us): Company X account.
- [Facebook](https://www.facebook.com/diffco.us/): Company Facebook page.
- [Behance](https://www.behance.net/diffco): Design work.

## Optional

- [Privacy Policy](https://diffco.us/privacy-policy/)
- [Sitemap](https://diffco.us/sitemap.xml)