Daniel Jasinski - Senior Software Engineer

Q: Where is Daniel based?

Daniel is based in Rzeszów, Poland .

Q: What languages does Daniel speak?

Daniel speaks the following languages: Polish (Native), English (Advanced) .

Q: How many years of experience does Daniel have?

Daniel has at least 14 years of experience. During this time, Daniel has worked in at least 2 different roles and for 3 different companies . The average length of individual experience is 5 years and 9 months . Note that Daniel may not have shared all experience and actually has more experience.

Q: What is Daniel's latest experience?

Daniel's most recent position is Senior Software Engineer at Sii Poland .

Q: What companies has Daniel worked for in recent years?

In recent years, Daniel has worked for Sii Poland .

Q: Which industries is Daniel most experienced in?

Daniel is most experienced in industries like Information Technology (IT) , Banking and Finance , and Food and Beverage . Daniel also has some experience in Transportation and Logistics , Media and Entertainment and Publishing .

Q: Which business areas is Daniel most experienced in?

Daniel is most experienced in business areas like Information Technology (IT) and Supply Chain Management .

Q: Which industries has Daniel worked in recently?

Daniel has recently worked in industries like Banking and Finance , Food and Beverage , and Information Technology (IT) .

Q: Which business areas has Daniel worked in recently?

Daniel has recently worked in business areas like Information Technology (IT) .

Recommended expert

Rzeszów, Poland

Experience

Feb 2020 - Present

6 years 2 months

Senior Software Engineer

Sii Poland

Built a microservices-based backend for tracking system using Go (Golang), achieving sub-100ms response times.
Implemented gRPC for real-time communication between microservices, reducing latency by 40%.
Designed and optimized PostgreSQL schemas for transaction processing and user account management.
Set up Apache Kafka for event sourcing in a fraud detection system, enabling real-time transaction analysis.
Implemented serverless functions using AWS Lambda for processing transaction notifications.
Configured AWS RDS with read replicas for high availability and performance.
Designed and implemented a CI/CD pipeline using GitHub Actions, enabling frequent and reliable deployments.
Set up Prometheus and Grafana for monitoring transaction processing and system health.
Automated infrastructure provisioning using Terraform, reducing setup time by 60%.
Developed an event-driven notification system using Apache Kafka, processing 1M+ events daily.
Built a RESTful API for order management using Python Flask, ensuring seamless integration with mobile apps.
Implemented Redis for caching restaurant menus and order statuses, reducing database load.
Designed and optimized DynamoDB tables for storing real-time order data.
Set up RabbitMQ for asynchronous communication between order processing and delivery services.
Deployed the application on AWS ECS Fargate, ensuring scalability during peak hours.
Configured AWS SNS for sending push notifications to delivery partners and customers.
Implemented AWS Lambda for processing payment status updates and refunds.
Set up centralized logging using the ELK stack for troubleshooting and analytics.
Designed and implemented a disaster recovery plan using AWS Backup and cross-region replication.
Developed a microservices-based backend for a SaaS platform using Node.js and Express.js, ensuring scalability.
Implemented Redis for caching frequently accessed user data, reducing API response times.
Designed and optimized PostgreSQL schemas for storing user data and application settings.
Set up Apache Kafka for event-driven updates to user dashboards and notifications.
Deployed the application on Kubernetes (EKS) for high availability and scalability.
Configured AWS SNS for sending push notifications to users.
Implemented AWS Lambda for processing user uploads and transformations.
Set up centralized logging using the ELK stack for troubleshooting and analytics.
Designed and implemented a disaster recovery plan using AWS Backup and cross-region replication.
Configured Prometheus and Grafana for monitoring API performance and system health.

Oct 2014 - Dec 2019

5 years 3 months

Software Developer

Connected Digital Ltd

Developed backend microservices in Golang for image metadata management and user content feeds, leveraging Go’s high concurrency support.
Built a serverless image processing pipeline using AWS Lambda and S3 for a photo-sharing app.
Designed and optimized DynamoDB tables for storing media metadata and user interactions.
Set up Apache Kafka for event-driven updates to user feeds and notifications.
Deployed the application on Kubernetes (EKS) for high availability and scalability.
Configured AWS CloudFront for CDN to improve media delivery times for global users.
Implemented AWS Lambda for processing media uploads and transformations.
Set up centralized logging using the ELK stack for troubleshooting and analytics.
Built high-throughput APIs using Golang for real-time shipment tracking, replacing performance bottlenecks in legacy Python code.
Developed an event-driven architecture using AWS EventBridge and SQS for a logistics tracking system.
Built a RESTful API for shipment tracking using Python Flask, ensuring seamless integration with mobile apps.
Implemented Redis for caching frequently accessed shipment data, reducing database load.
Designed and optimized DynamoDB tables for storing real-time shipment data.
Set up RabbitMQ for asynchronous communication between shipment processing and tracking services.
Deployed the application on AWS ECS Fargate, ensuring scalability during peak hours.
Configured AWS SNS for sending push notifications to drivers and customers.
Implemented AWS Lambda for processing shipment status updates and notifications.
Set up centralized logging using the ELK stack for troubleshooting and analytics.
Designed and implemented a disaster recovery plan using AWS Backup and cross-region replication.

Sep 2011 - Oct 2014

3 years 2 months

Software Developer

University of Information Technology and Management

Developed a GraphQL API for a social media app, reducing over-fetching and improving client-side performance by 30%.
Implemented WebSocket-based real-time notifications for user interactions (likes, comments, messages).
Designed a microservices architecture using Go (Golang) for high-performance backend services.
Utilized Apache Kafka for event-driven updates to user feeds and notifications.
Set up MongoDB for storing user-generated content, ensuring scalability and flexibility.
Implemented OAuth2 and JWT-based authentication for secure user access.
Deployed the application on Kubernetes (EKS) for seamless scaling during peak traffic.
Configured Datadog for end-to-end observability, enabling quick troubleshooting of performance bottlenecks.
Developed a high-performance backend for a mobile gaming app using Go (Golang), achieving low-latency gameplay.
Implemented Redis for caching frequently accessed game data, reducing API response times.
Designed and optimized DynamoDB tables for storing real-time game data.
Set up Apache Kafka for event-driven updates to game state and player interactions.
Deployed the application on Kubernetes (EKS) for high availability and scalability.
Configured AWS CloudFront for CDN to improve game asset delivery times for global users.
Implemented AWS Lambda for processing in-game purchases and receipts.
Set up centralized logging using the ELK stack for troubleshooting and analytics.

Industries Experience

See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.

Experienced in Information Technology (14.5 years), Banking and Finance (6 years), Food and Beverage (6 years), Transportation (5 years), and Media and Entertainment (5 years).

Information Technology

Banking and Finance

Food and Beverage

Transportation

Media and Entertainment

Business Areas Experience

The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.

Experienced in Information Technology (14.5 years) and Supply Chain Management (5 years).

Information Technology

Supply Chain Management

Summary

Senior Backend Engineer with over 12 years of hands-on experience delivering robust backend systems and infrastructure for both startups and large-scale platforms. Focused on building reliable, maintainable services using Go, and also well-versed in Python, Java, and Node.js. Skilled in architecting microservices and event-driven systems, with a strong emphasis on performance tuning and operational stability. Experienced in DevOps practices including CI/CD pipelines, infrastructure provisioning, and cloud-native deployments on AWS. Brings a systems-thinking mindset to backend engineering—designing solutions that are efficient, scalable, and easy to evolve.

Skills

Backend Development: Graphql, Grpc, Rest Apis, Java, Go (Golang), Python, Node.js (Typescript, Javascript), Apache Kafka, Rabbitmq, Prometheus, Grafana, Datadog, Elk
Aws: Ec2, Ecr, Ecs, Cks, Fargate, Api Gateway, Eventbridge, Sqs, Sns, Lambdas, Cdk, S3, Dynamodb, Rds
Devops: Docker, Kubernetes, Github Actions, Ci/cd Designing, Aws Ec2, Ecr, Ecs, Eks, Terraform
Database: Postgresql, Mongodb, Mysql, Redis, Dynamodb, Cassandradb, Neo4j

Languages

Polish

Native

English

Advanced

Education

Oct 2011 - Jun 2012

University of Information Technology and Management

Master’s degree, Computer Science · Computer Science · Rzeszów, Poland

Oct 2007 - Jun 2011

University of Information Technology and Management

Bachelor’s degree, Computer Science · Computer Science · Rzeszów, Poland

Profile

Created

October 2025

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Frequently asked questions

Do you have questions? Here you can find further information.

Where is Daniel based?

Daniel is based in Rzeszów, Poland.

What languages does Daniel speak?

Daniel speaks the following languages: Polish (Native), English (Advanced).

How many years of experience does Daniel have?

Daniel has at least 14 years of experience. During this time, Daniel has worked in at least 2 different roles and for 3 different companies. The average length of individual experience is 5 years and 9 months. Note that Daniel may not have shared all experience and actually has more experience.

What roles would Daniel be best suited for?

Based on recent experience, Daniel would be well-suited for roles such as: Senior Software Engineer, Software Developer.

What is Daniel's latest experience?

Daniel's most recent position is Senior Software Engineer at Sii Poland.

What companies has Daniel worked for in recent years?

In recent years, Daniel has worked for Sii Poland.

Which industries is Daniel most experienced in?

Daniel is most experienced in industries like Information Technology (IT), Banking and Finance, and Food and Beverage. Daniel also has some experience in Transportation and Logistics, Media and Entertainment and Publishing.

Which business areas is Daniel most experienced in?

Daniel is most experienced in business areas like Information Technology (IT) and Supply Chain Management.

Which industries has Daniel worked in recently?

Daniel has recently worked in industries like Banking and Finance, Food and Beverage, and Information Technology (IT).

Which business areas has Daniel worked in recently?

Daniel has recently worked in business areas like Information Technology (IT).

What is Daniel's education?

Daniel holds a Master in Computer Science from University of Information Technology and Management and a Bachelor in Computer Science from University of Information Technology and Management.

What is the availability of Daniel?

The availability of Daniel needs to be confirmed.

What is the rate of Daniel?

Daniel's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.