Nikita Petrich
Freelance Senior Full-Stack & AI Engineer

Nikita Petrich

“Anything done manually twice gets automated”
LLM integrationRAGAI engineeringAgentic CodingTypeScriptPythonBackend (NestJS · Node.js · FastAPI)Frontend (Next.js · React · Angular)Clean ArchitectureGDPR-compliant

I am a freelance Senior Full-Stack & AI Engineer focused on AI: LLM integration, RAG and AI-assisted automation – from architecture through to stable production operation.

My guiding principle: anything done manually twice gets automated. That applies to my clients' processes just as much as to my own work. In logistics, a route management system I built saves up to 1,000 hours per employee per year through automated document processes; in retail, up to 40 hours of administrative work per month; at a notary's office, clients' phone enquiries drop by up to 70 %.

My own development follows the same principle: I work with modern agentic coding and AI engineering workflowsspec-driven, AI-assisted and with automated tests and reviews. That gives me high delivery speed at consistent quality, with no compromise on maintainability, traceability and stability.

I'm at home in both backend (NestJS · Node.js · FastAPI) and frontend (Next.js · React · Angular) – open to full-stack, backend-only or frontend-only work.

I work independently, remotely and asynchronously. A clear goal is enough – I structure the path there myself. I document decisions, code arrives tested and ready for review, and I raise technical risks early. Communication in German and English.

More than 7 years of experience in LegalTech, HealthTech, e-commerce, EdTech and logistics – both as part of a 20-strong engineering team on an AI-assisted LegalTech platform with more than 3,000 customers and as the sole developer responsible for architecture, operations and further development.

Does this fit what you have in mind? Then I'd be glad to have a no-obligation intro call.

Book a free intro call

Focus

LLM integrationRAGAI-assisted automationAgentic Coding / AI-EngineeringTypeScriptPythonBackend (NestJS · Node.js · FastAPI)Frontend (Next.js · React · Angular)PostgreSQLClean ArchitectureMicroservicesCI/CDDockerGDPR-compliant AI architecture

Projects

Testimonials

What clients and project colleagues say about working together. Every testimonial is verifiable through its source (LinkedIn / Malt).

LinkedIn
Testimonial
Aslan Aiaev
Manifest Law

„Nikita and I went through onboarding together at Manifest OS and then worked closely in the same team for a considerable time. He was a Senior Fullstack Engineer there, involved among other things in consolidating the separate portals into the unified one — a rebuild that required merging data model and UI, and correspondingly a lot of care and context. What stayed with me most about working with him: Nikita is extremely self-reliant. He found his way into a complex, grown codebase without anyone having to guide him through it, and was always approachable whenever I had questions. His code was clean, type-safe and tested — he consistently applied SOLID and clean code principles and built reusable components and utilities that the whole team benefited from. That made reviews with him productive rather than tedious. Worth mentioning as well: he didn’t just work on his own tickets. He repeatedly tracked down existing bugs in the system that nobody had noticed before and fixed them directly. A real asset to the team, both technically and personally. I’d work with him again any time and recommend him without reservation.“

Project teamManifest OS — AI-assisted immigration platform
LinkedIn
Testimonial
Artem Puliavin
Manifest Law

„As tech lead for the B2C area I worked with Nikita at Manifest OS on the HubSpot, Cal.com and Bluedot AI integration — him as a Senior Fullstack Engineer, me on the lead side. Specifically it was about event-driven enrichment of initial legal consultation leads: meeting recordings are transcribed via Bluedot, processed further through a webhook and a queue, evaluated by an LLM, and the structured results flow back into the core systems automatically. A chain with plenty of failure modes, which had to be built accordingly resilient (retry, idempotency). Nikita delivered this integration entirely on his own responsibility. I never had to step in — he kept me updated with short, precise status updates, escalated open decisions in time and carried the rest himself. The result was a fully functional AI integration running in production, cleanly implemented and delivered on time. For me that’s the best illustration of how he works: a high degree of autonomy combined with transparent communication. I can clearly recommend Nikita.“

Project teamManifest OS — AI-assisted immigration platform
LinkedIn
Testimonial
Sagar Anne
Manifest Law

„As Product Manager I owned the Amplitude analytics project at Manifest OS; Nikita, as a Senior Fullstack Engineer, was the one who carried the implementation. He designed and implemented the application-wide event tracking, instrumented all relevant business user flows, tested and validated the events and created the data foundation that made weaknesses and friction points in the user journey visible in the first place. What made the collaboration so easy from a PM perspective is how autonomously Nikita worked: he grasped requirements quickly, identified gaps himself and asked targeted questions rather than making assumptions. He was also strong cross-functionally: he worked closely with our designers and consistently followed the design system instead of building his own one-offs, which noticeably supported the visual consistency of the platform.“

Project teamManifest OS — AI-assisted immigration platform
LinkedInMalt
Testimonial
Suraj Kakar
AITOI

„We are extremely happy with Nikita Petrich's work as a freelance developer! He made a decisive contribution to our AI toy project and delivered a clear, secure and scalable solution. Nikita built a Next.js app for setting the toy up easily as well as a Next.js progressive web application (PWA) for the dashboard through which parents can follow, filter and analyse their children's play sessions. He used state-of-the-art technologies for the implementation, among them React, Next.js 15, Tailwind CSS, shadcn, Supabase and Docker, along with CI/CD pipelines and unit tests to ensure the quality, security and reliability of the applications. We particularly value Nikita's professionalism, his technical expertise and his considered approach — we would work with him again at any time and can recommend him without reservation.“

ClientAITOI — AI toy (setup app & PWA dashboard)
Malt
Testimonial
Daniel Kmiotek
LeXtorByte UG (haftungsbeschränkt)

„We have been working with Nikita for three months now. His performance and commitment clearly exceed what you would expect from a freelancer. He supports us in developing software for notary offices and works through the frontend requirements (React TS) quickly and reliably. Beyond that, he improves the quality of the source code on his own initiative and contributes substantially to the quality assurance of the software. We very much enjoy working with Nikita and recommend him without reservation. He is an excellent choice when frontend solutions need to be implemented cleanly and in a user-friendly way.“

ClientDiNo — digital notary office
Malt
Testimonial
Harry Diwert
HD Autoservice, Pulverbeschichtung & Fahrzeugteilehandel

„I would like to recommend Nikita Petrich without reservation for his outstanding work as a full stack developer. He built a bespoke ERP system for our company that has substantially improved our business processes. Points worth highlighting: Technical expertise: using technologies such as React, NestJS, GraphQL and MariaDB, Nikita created a powerful and user-friendly ERP system tailored precisely to our requirements. Efficient inventory management: the solution he implemented allows precise real-time tracking of our stock, which has markedly increased our efficiency. Invoicing: the function for generating PDF invoices has sped up our workflows and minimised errors. Professional collaboration: Nikita convinced us with clear communication, proactive suggestions and thorough training during the implementation. Reliable support: even after the project was completed he is always available for questions and adjustments. Nikita combines technical expertise with a solution-oriented way of working and a high degree of professionalism. We are delighted with his work and can recommend him to any company looking for bespoke software solutions. Many thanks for the excellent collaboration!“

ClientAccounting OS — ERP & inventory management system
MaltLinkedIn
Testimonial
Ahmed Buraa Hameed
XU Group

„I am happy to confirm that we have contracted Nikita from July 2021, to February 2023. Nikita was responsible for developing the front-end and the back-end of the platform. Nikita worked independently on our platform and helped us provide the best UI/UX experience due to his experience in the Front-end field. We got to know Nikita as a competent, friendly and engaged person. We believe that Nikita has a tremendous amount of potential and would be an outstanding addition to the team. I would have no reservations about hiring him again and I am confident in recommending Nikita for employment or external support as a contractor.“

Project teamXU Navigator — enterprise learning platform
LinkedIn
Testimonial
Behdad Tabrizi
XU Group

„I am glad to give Nikita Petrich a positive reference for his work in our joint project for the XU Group. During our collaboration Nikita worked as a full-stack developer focusing on Angular in the frontend and NestJS in the backend. In that role he consistently convinced through his technical expertise, his reliability and his structured way of working. His ability to grasp complex requirements quickly and turn them into efficient, clean solutions deserves particular mention. Nikita was not only a strong team player professionally but also an asset to the project as a person. Communication with him was always open, constructive and goal-oriented. I can recommend Nikita and am convinced that he will be a valuable support in future projects as well.“

Project teamXU Navigator — enterprise learning platform
LinkedIn
Testimonial
Nikita Herndlhofer
Manifest Law

„As a tech lead from another team, I’ve had the opportunity to collaborate with Nikita on several projects. Nikita consistently delivered strong execution, sound judgment, and the ability to get things done efficiently, even across team boundaries!“

Project teamManifest OS — AI-assisted immigration platform

Skills & technologies

My skills

Hard skills18

01AI, LLM & AI engineering
LLM integrationRAG (retrieval augmented generation)Prompt EngineeringEmbeddingsVector databasespgvectorSemantic searchDocument analysisOCRLangChainOpenAI APIAzure OpenAIAnthropic Claude APIHugging FaceOllamaAI agentsAgentic Software EngineeringAI-assisted automationAI EngineeringGenAIArtificial intelligenceGDPR-compliant AI architecture
02Agentic coding
Claude CodeCursor AIGitHub CopilotCode RabbitChatGPTLovablev0Claude Code HooksSlash CommandsAgent SkillsSubagentsMulti-agent workflowsModel Context Protocol (MCP)Agentic CodingContext EngineeringSpec-Driven DevelopmentAgentic pull request workflowsAI-assisted test generation
03Programming languages
TypeScriptJavaScriptPythonC#SQLBashHTMLCSSSCSSXMLJSONYAMLUML
04Backend & frameworks
Node.jsNestJSExpress.jsFastifyFastAPIFlaskASP.NET CoreASP.NET Core Web API.NET CoreMERNMEANHeadless CMSStrapiDirectusGraphQLREST APIOpenAPISwaggergRPCWebSocketsWebhooksMessage QueuesBullMQRabbitMQBackend developmentObject-oriented programming (OOP)
05Frontend
ReactNext.jsAngularReact NativeIonicCapacitorCross-platform developmentiOSAndroidReduxNgRxRxJSTanStack QueryReact Hook FormReact RouterAxiosZodTailwind CSSshadcn/uiMaterial UI (MUI)Angular MaterialFluent UISingle Page Application (SPA)Progressive Web App (PWA)Server-Side Rendering (SSR)Internationalisation (i18n)Frontend developmentWeb development
06Design & UX
FigmaWireframingPrototypingDesign SystemDesign TokensComponent librariesStorybookUI/UX DesignUI implementationResponsive DesignMobile FirstAccessibility (WCAG)UsabilityUser guidanceOnboarding flowsInformation architectureUX Writing
07Databases & data
PostgreSQLMySQLMariaDBMicrosoft SQL Server (MSSQL)MongoDBMongooseNoSQLCloud FirestoreSQLiteRedisPrismaMikroORMTypeORMDrizzle ORMEntity Framework CoreData modellingData architectureDTOsData synchronisationETLCSV processingCachingIdempotency
08DevOps, cloud & infrastructure
DockerDocker ComposeCI/CDGitHub ActionsGitLab CIAzure PipelinesJenkinsNginxSentryDatadogMonitoringObservabilityLinuxUbuntuSelf-HostingMicrosoft AzureAzure FunctionsAzure App ServiceAzure Blob StorageAzure SQLGoogle Cloud Platform (GCP)Amazon Web Services (AWS)HetznerIONOSDigital OceanVercelSupabaseSupabase RealtimeSupabase Edge FunctionsFirebaseCloud FunctionsCloud StorageFirebase Cloud Messaging (FCM)Firebase HostingDevOpsDevSecOps
09Networking & protocols
TCP/IPIP networksDNSHTTP/HTTPS
10Auth & security
JWTOAuth 2.0Single Sign-On (SSO)better-authFirebase AuthenticationFirebase Security RulesAuthenticationRole-Based Access Control (RBAC)Row Level SecuritySSL/TLSEnd-to-end encryptionO365 IdentityMicrosoft Entra ID (formerly Azure Active Directory)Secure by DesignIT security
11Architecture & principles
Software architectureClean ArchitectureSOLIDDesign PatternsDomain-Driven DesignSeparation of ConcernsDependency InjectionMicroservicesEvent-Driven ArchitectureMonorepoNxTurborepoScalable architectureSystem integrationInterface developmentAPI integrationThird-party system integrationPlatform migrationMiddlewareAPI-FirstResilience PatternsType safetyMVP development
12Ways of working & methodology
Agile methodsScrumKanbanScrumbanRequirements EngineeringRequirements analysisSprint PlanningBacklog RefinementRetrospectiveDaily Stand-up
13Engineering practices
Clean CodeCode reviewsRefactoringLegacy modernisationContinuous IntegrationContinuous Delivery
14Consulting & business
IT consultingSoftware developmentProject managementIT strategyDigital strategyDigital transformationProcess digitalisationProduct ownershipEntrepreneurship
15Data protection & compliance
GDPRPrivacy by DesignData minimisationData processing agreement (DPA)EU AI ActAI GovernanceGoBDAudit-proof recordsEU hostingDigital sovereigntyGerman Accessibility Reinforcement Act (BFSG)European Accessibility Act (EAA)
16Testing & QA
JestVitestCypressPlaywrightReact Testing LibraryUnit TestingIntegration testsEnd-to-end testsPostmanAPI testingTest automation
17Tooling
GitGitHubGitLabHuskynpmpnpmCLI (Command Line Interface)Visual Studio CodeVisual StudioJiraConfluenceLinearTrelloAzure DevOpsMiroSlackMicrosoft TeamsGoogle CalendarGoogle Workspace (Meet, APIs)BluedotHubSpotCal.comn8nAmplitudeProduct Analytics
18Domains & industries
LegalTechGovTechLaw firm softwareNotary servicesClient portalDocument managementHealthTechMedical technologyMaintenance managementERPInventory managementWarehouse managementInvoicingOrder managementCRMAccountingMaster data managementMulti-TenancyStripeSEPAPayment processingLogisticsRoute planningPDF generationDOCX generationDigital archivingEdTechE-LearningLearning Management System (LMS)Video streamingSocial MediaIoTDevice PairingConsumer ElectronicsSaaSPlatform development

Soft skills3

19Communication & presentation
Professional communicationClear communication (German/English)Proactive communicationPresentation skillsPublic SpeakingStakeholder communicationConstructive feedbackTechnical documentation
20Teamwork & collaboration
TeamworkFitting into existing teamsCollegial collaborationKnowledge sharingRemote collaborationAsynchronous collaborationCross-functional collaboration
21Reliability & work ethic
ReliabilitySense of responsibilitySelf-directed workingFast response timesResults-drivenSolution-orientedWillingness to learn

Profile1

22Roles & profile
Senior Full-Stack EngineerAI EngineerSoftware EngineerSoftware developerFull-stack developerFrontend developerBackend developerWeb developerSoftware architectFreelance DeveloperFreelance software developerTechnical advisorIT specialist for application developmentRemote WorkGerman (native)English B2Business EnglishMunichDACH

Certificates

Completed courses and assessed qualifications. Each card shows the full scope — key facts, contents and syllabus — and links to the certificate as a PDF. All certificates on one page.

Working together

Have a project that fits this profile? Three ways in, depending on how firm it already is.