Sebastian Sastre

Sebastian Sastre

Mentor
5.0
(26 reviews)
US$25.00
For every 15 mins
13
Sessions/Jobs
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First 15 mins free for your first session
ABOUT ME
I'll help with Software Engineering challenges in the full stack.
I'll help with Software Engineering challenges in the full stack.

I bring over a decade of experience in a full-stack development across diverse technologies crucial for SaaS and backend solutions. I comfortably navigate all the communication nuances from business, product, design and engineering back and forth. My expertise lies in collaborating with diverse functional teams and engineering colleagues to design highly reliable solutions, particularly with high-throughput backend engineering as for example in Telna where I've help the their service go from 9Kops to 27Kops. I thrive in distributed teams and diverse multilingual/cultural environments and I'm very open yet currently having a preference to work with great teammates in a blockchain related project with Rust.

+10/y remote work experience in diverse small distributed teams and
+20/y total in software engineering (very strong at OOP)
5-star mentor at codementor.io
https://www.codementor.io/sebastianconcept

Stanford's Machine Learning course:
https://www.coursera.org/account/accomplishments/certificate/TTEZAZDQ59B6

Some of the tech and stacks:
JavaScript (ES6), NodeJS, Smalltalk, Swift, Docker, GCloud, AWS, MongoDB, SvelteKit, ReactJs, NextJS, VueJs, Angular, Meteor

Portuguese, Spanish, English
Brasilia (-03:00)
Joined November 2014
EXPERTISE
15 years experience
I have 15 years of experience doing software done with pure Object Oriented technologies. Covering areas like control systems, payment ga...
I have 15 years of experience doing software done with pure Object Oriented technologies. Covering areas like control systems, payment gateways, management systems, desktop system, LAN systems and web applications. I'm the author of this SaaS http://airflowing.com
5 years experience
I've implemented Mapless* that uses as backend MongoDB (Mapless can also use Redis and Postgres). I help on several startups that uses it...
I've implemented Mapless* that uses as backend MongoDB (Mapless can also use Redis and Postgres). I help on several startups that uses it from different languages. I really like to use MongoDB. It's very nice to work with JavaScript for a document oriented database. Drop me a line on what you need to get solved with it. * http://sebastianconcept.github.io/Mapless/
3 years experience
I primarily use github and gitlab for projects. I even contribute on some open source projects. For me the best about git is to be able ...
I primarily use github and gitlab for projects. I even contribute on some open source projects. For me the best about git is to be able to take a Jenkins (or any other continuous integration system) and automate deloyment.
7 years experience
I use jQuery intensely. I help 5 startups do parts of their frontend based on jquery. It has a really nice API. Quite object oriented. It...
I use jQuery intensely. I help 5 startups do parts of their frontend based on jquery. It has a really nice API. Quite object oriented. It's just good. I can help you to get things done with it.
8 years experience
I've implemented http://airflowing.com which is a SaaS for small companies. This web aplication is rendered from the server side but we c...
I've implemented http://airflowing.com which is a SaaS for small companies. This web aplication is rendered from the server side but we can use all sort of frameworks for getting your html and CSS sorted.
7 years experience | 1 endorsement
JavaScript, with all its defects, is still one of my favorites. I'm using it more intesely on the last 7 years gradually doing more and m...
JavaScript, with all its defects, is still one of my favorites. I'm using it more intesely on the last 7 years gradually doing more and more frontend stuff. For airflowing I make intense use of jQuery and for other clients I use this framework I've released under MIT license: http://github.com/flow-stack/flow. With Angular I like to use directives a lot because things are more reusable and flexible that way. Here you can see a sample: http://github.com/sebastianconcept/25m
10 years experience
Basically I've implemented http://airflowing.com using seaside as foundation and my own framework on top of it. It's horizontally scalabl...
Basically I've implemented http://airflowing.com using seaside as foundation and my own framework on top of it. It's horizontally scalable and its object database is ACID compliant. Airflowing is a SaaS for service companies. Smalltalk is very powerful, I can help you to go really far. My favourite thing? Doing html5 Single Page Applications using this framework I've made to get productive on that: http://github.com/flow-stack/flow

REVIEWS FROM CLIENTS

5.0
(26 reviews)
Ilyass Nanaa
Ilyass Nanaa
October 2016
The meeting was great , very helpful guy , and patient with someone that doesn't have a good basic knowldge with Node.s or terminal and so on. Once again thank you :) i will get back to you as soon as possible .
Dag vB Bunkholt
Dag vB Bunkholt
July 2016
I have used more than a few mentors here, and Sebastian is truly standing out as the mentor that is sincerely interested in helping you, and goes that extra mile. I often come here when I'm in a hurry, and if I can get a hold on to Sebastian I know I can lower my shoulders. It once took all night all weekend, but Sebastian never gave up!
Nobuyuki Fujioka
Nobuyuki Fujioka
May 2016
Sebastian is very helpful.
Sebastian Weiss
Sebastian Weiss
May 2016
Thanks a lot. He was very helpful. My issue was solved. Sebastian did it! He knows a lot about Meteor and how to debug the code. He also gives me some security hints on how to improve my code. Thanks a lot
John Reynolds
John Reynolds
September 2015
He was great. Took the time to understand what needed to be done, then helped me resolve a couple issues along the way to the answer I was looking for. Will look for him again.
Nuvi
Nuvi
September 2015
Sebastian is a really knowledgeable guy with a great personality and learns quickly. He spent some time before our session showing me useful resources to help me get started with my project and showed me best practices with using Meteor, which I thought was really awesome of him. Then he started the session when we were ready to dive into my project request. He has been a great help with pointing me in the right direction and how to go about solving issues as a developer. Definitely recommend 5/5. Thanks again! :)
Chris McNabb
Chris McNabb
May 2015
Excellent! Great Debugging session!
Anton Loss
Anton Loss
March 2015
Excellent mentor, understands what I need very well, and gives fast helpful advice! Expert in Meteor
Andrew Mello
Andrew Mello
March 2015
One of the best Meteor developers around
Leigh Boone
Leigh Boone
March 2015
Sebastian was very helpful and gave me best practices as wel as help tacking down my issue
EMPLOYMENTS
Senior Software Engineer
Telna
2019-09-01-2023-08-01
  • Successfully led a team of four in a six-month effort to refactor the main backend code, effectively resolving tech debt issues t...
  • Successfully led a team of four in a six-month effort to refactor the main backend code, effectively resolving tech debt issues that were impeding containerization.
  • Developed and successfully implemented a Proof of Concept within 2 days to showcase the migration of the persistence framework from Voyage to Mapless.Achievements
  • Demonstrated a Rust caching system to extend the main backend capacity, currently above 25Kops and leveraged parts ofthe PoC to continuously expand production capacity beyond 1 Peta Byte in May 2023.
  • Added a stress testing layer with a custom Golang multithreaded client to produce synthetic traffic that guarantees SLAs.
Python
MongoDB
Bash
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Python
MongoDB
Bash
Jira
Test driven development
Docker
Smalltalk
Rust
Docker swarm
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Full-stack Software Engineer
Sulvo
2016-05-01-2018-12-01
  • Lead a team of 6 engineers at Sulvo and designed and implemented the next generation ad server in a JavaScript-based custom stack...
  • Lead a team of 6 engineers at Sulvo and designed and implemented the next generation ad server in a JavaScript-based custom stack.
  • Implemented the pipeline to automatically deploy globally acrosss regions using GCloud. Achievements
  • Implemented an automated deployment pipeline using GCloud, enabling global deployment across regions in a backward compatible way.
Meteor
Cloud
Docker
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Meteor
Cloud
Docker
React
Cloudflare
JavaScript
CI/CD
Vue.js
DevOps
AWS
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Full-stack Software Engineer
StarterSquad
2015-04-01-2016-08-01
  • Mentored 2 junior developers from Vandebron.nl in using AngularJS to develop new features for their platform in the energy sector...
  • Mentored 2 junior developers from Vandebron.nl in using AngularJS to develop new features for their platform in the energy sector. Additionally, I worked with CX teams to complete frontend tasks using both AngularJS and ReactJS, ultimately improving the user experience and completing tasks weekly in a timely and efficient manner.
  • Developed and published in the AppStore a Swift native app for a client from The Netherlands. Additionally, developed the app's NodeJS backend and Vue dashboard frontend, creating a complete solution.
  • Developed an MVP for two founders of a dairy industry startup in the Netherlands in one week. The founders were able to secure a Series A funding of €4M in the following 2 months.
Angular
Meteor
JavaScript
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Angular
Meteor
JavaScript
Swift
iOS
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PROJECTS
2014
Schema-less persistence for Smalltalk with support for multiple backends. Ambition Mapless gives you performant state plasticity and hig...
Schema-less persistence for Smalltalk with support for multiple backends. Ambition Mapless gives you performant state plasticity and high availability in a scale that goes beyond one Smalltalk image and without backend vendor locking nor object-mapping impedance mismatch. Supported backends 1. MongoDB 2. Redis 3. Memory 4. PostgreSQL 5. UnQLite 6. SQLite
Smalltalk
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Smalltalk
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2022
Algorithmically sharded repository for Pharo. Ambition Matter gives you a performant cache of objects with a basic Dictionary API and sc...
Algorithmically sharded repository for Pharo. Ambition Matter gives you a performant cache of objects with a basic Dictionary API and scalable by the number of Pharo images configured in the clients. Features 1. Basic Dictionary API. 2. Simplicity. No transactions, no persistence, just a big cache of Pharo objects. 3. Horizontally scalable by adding nodes to the shard. 4. No need to create and maintain schemas. 5. Homogeneously distributed data load. 6. Fast as a Dictionary can be.
WebSocket
Smalltalk
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WebSocket
Smalltalk
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