Senior Fullstack Developer (.NET + React), DevOps & Team Lead
My name is Maksim Sitnikov — a Senior Fullstack developer (.NET + React), DevOps engineer and team lead from Moscow with 8+ years of commercial development. My core stack is C# / .NET (8–10), ASP.NET Core, React and TypeScript, Python and SQL; in production I work with Docker, Kubernetes, CI/CD and monitoring (Prometheus, Grafana). I love automating processes and sharing knowledge on GitHub and Habr. Currently I work on the backend of the cloud payment system XPay at Xpress Super App. English — A2.
My projects include a service for submitting applications via the State Services API, image processing tools and libraries for cryptography work. I develop server-side, web and desktop applications and lead them from idea to deployment.
A dedicated focus is data and analytics: designing and maintaining data warehouses, ETL processes and OLAP reporting (Apache Airflow, Kafka, RabbitMQ, Pentaho, Apache Superset, MS Analysis Services). I have led a development team, and started my career as a system administrator — so I'm equally comfortable in the code and in the infrastructure.
I strive to write clean and testable code, build reliable pipelines and believe in the power of automation. In my spare time I participate in hackathons, solve problems on Codewars and raise children — this helps me look at problems from different angles.
More code examples can be found on GitHub, and articles on Habr. I'm always open to new ideas and collaboration.
Experience creating a service for submitting applications via the State Services API.
Improving image quality for subsequent analysis and processing.
Integration with the State Services test environment and vulnerability in the Payments section.
WorkingCalendar and workingcalendar.ru website — automating the working calendar in the database.
Working calendar in Microsoft SQL Server, MySQL, PostgreSQL.
State Services API interaction system (EPGU): automating application submission and result processing.
Haze removal (dark channel, transmission, adaptive lighting). C# application.
Converting text to Morse code and back. Algorithmic problems in C#.
Calorie tracking and menu planning on Xamarin.
Backend of the cloud payment system XPay on .NET.
Development and maintenance of AntiFraud system for Sber's telecom division.
LegalTech platform: consulting, management accounting, integration with state services.
LegalTech: automating document management and legal work.
Custom development: web applications, prototyping, client work.
Higher education. Programme: "IT Management in Organizations".
Higher education. Qualification "Economist", major "Accounting, Analysis and Audit".
Write backends and utilities, use async/await and lock, Interlocked, Mutex, Monitor, Semaphore, ConcurrentDictionary, Span<T>, LINQ, profile memory and allocations.
Schema design, T-SQL, execution plan optimization, indexing, analytical queries.
CLI/scripts for CI/CD, integrations (REST/WebSocket), simple Flask services.
TypeScript for frontend and tooling, REST interaction, build configuration, testing, publishing and storage in private registry.
Semantic markup, grids, responsive design and micro-animations, dark theme support.
Microservices, configuration, logging, testing, containerization.
REST design, authorization, versioning, client generation by OpenAPI.
Support of existing systems, migrations to .NET Core, performance optimization.
Components, state, JS interop, publishing, API and SignalR integration.
Code First, migrations, tracking/NoTracking, LINQ optimization, query profiling, concurrency.
High-performance data access, manual mappings, multimapping, split for read/write.
Contracts, streams, inter-service communication, load balancing/retries.
Hubs, groups, backplane scaling, authorization.
Service support, migration paths, contract compatibility.
React + TypeScript, components, routing, API interaction.
Component fixes, REST integration, version migrations as needed.
Mobile and desktop applications on Xamarin.Forms and .NET MAUI.
YAML pipelines, cache/artifacts, environments, agents, Helm chart deployment from CI.
Creation and support of build and release pipelines in TFS 2018, release templates, Azure DevOps agent pools.
CI for various projects, build quality, Docker Registry integration.
PR processes, rebase/merge, branch policies and CI checks.
Provisioning, idempotency, roles, inventory, secrets (vault), configuration rollout.
Build configuration, artifacts, parameters, VCS/Issue-tracker integration.
Windows/Linux agent configuration, tags, parallel builds, secret security, YAML pipelines.
Projects, environments, variables, Runbooks, CI-server integration, Tenants.
Workflows, matrix builds, reusable actions, secrets, deployment to GitHub Pages and Docker Registry.
Dockerfile, multi-stage builds, docker-compose, private image registries.
Multi-container environments, networks, volumes, override files, profiles for dev/test/prod.
Deployment/StatefulSet, ConfigMap/Secret, HPA, services, cluster monitoring.
Custom charts, values, repositories, deployment through GitLab CI.
Ingress resources, annotations, cert-manager, load balancing and security.
Creation and publishing of NuGet packages, .nuspec work, private feeds.
Verdaccio setup and use for caching npm packages and private modules.
Docker image storage and management, vulnerability scanning, replication between locations.
Normalization, indexes (btree/gin), EXPLAIN/ANALYZE, migrations.
Stored procedures, triggers, indexes, SSRS/SSAS for reporting/OLAP.
Collection schemas, aggregation pipelines, indexes, backup.
Cypher queries, graph relationships, optimization for reporting/costs.
Data caching, distributed locks, Pub/Sub, Streams, Sentinel/Cluster.
Indexes, mappings, aggregations, Kibana dashboards, ELK stack for logging.
Cube modeling, dimensions/facts, aggregations, access rights.
ETL processes, reports, dashboards, Big Data work.
Dashboard creation, SQLAlchemy work, integration with various data sources.
Creation and management of workflows, integration with various data sources.
Report design, parameters, data sources, publishing and access.
Idempotency, pagination, response codes, contract-first approach.
Subscriptions, reconnect, backpressure, binary message exchange.
Extended management protocol for RTPengine.
Documentation, schema validation, SDK generation and compatibility checks.
Authorization Code/Client Credentials, refresh tokens, secure secret storage.
Exchange/queue, acknowledgments, consumer idempotency, retry policies.
Topics/partitions, consumer groups, end-to-end event processing.
Metric collection, alert rules, exporters, service discovery.
Dashboards, annotations, alerts, panel sharing.
Elasticsearch + Logstash + Kibana: collection, parsing and visualization of application and infrastructure logs.
Request tracing across microservices, OpenTelemetry SDK integration, latency analysis.
Virtual host configuration, TLS, caching, proxying to applications.
Virtual host configuration, TLS, caching, routing, load balancing, proxying to applications.
SSL certificates from Let's Encrypt in both standalone applications and in clusters.
Sites/app pools, deployment, logs, restrictions and security.
Virtual hosts, mod_proxy, mod_ssl, URL rewriting, .htaccess and access control.
Automatic certificate acquisition, reverse proxy, Caddyfile, API management.
Bounded Context, Aggregate, Ubiquitous Language, anti-corruption layers.
SRP, OCP, LSP, ISP, DIP in practice, decomposition and testability.
Command/Query models, Event Sourcing, consistency and integration.
Simple interfaces, minimal dependencies, clear architecture.
Red-green-refactoring, test pyramids, fast unit tests.
Use Cases, Entities, Interface Adapters, external layers and testability.
Sprint planning, grooming, retro, flow metrics.
Unit tests, parameterized tests (Theory/TestCase), CI integration, code coverage.
Mock objects for unit tests, call verification, return value setup.
Browser test automation, Page Object Model, parallel execution, CI integration.
Request collections, environments, automated tests, Newman integration in CI/CD pipelines.
Server services, permissions/services, environment configuration for .NET and agents.
Ubuntu/CentOS, systemd, network settings, security and updates.
Reach out on Telegram or by email — open to interesting technical questions and conversations. Code and projects are on GitHub.
