Blogg
Här finns tekniska artiklar, presentationer och nyheter om arkitektur och systemutveckling. Håll dig uppdaterad, följ oss på Twitter
Dynamic Multi Tenancy with Spring Boot, Hibernate and Liquibase Part 2: Outlining an Implementation Strategy for Multi Tenant Data Access
// Björn Beskow
In this part, we will outline an implementation strategy to encapsulate a Multi Tenant Data Access mechanism as a transparent, isolated Cross Cutting Concern with little or no impact on the application code. We will also introduce the notion of Database Schema Migration and explain why it is a critical part of a Multi Tenancy mechanism.
Dynamic Multi Tenancy with Spring Boot, Hibernate and Liquibase Part 1
// Björn Beskow
Multi Tenancy usually plays an important role in the business case for SAAS solutions. Spring Boot and Hibernate provide out-of-the-box support for different Multi-tenancy strategies. Configuration however becomes more complicated, and the available code examples are limited. In the first part of this blog series, we’ll start by exploring the Multi Tenancy concept and three different architectural patterns for multi tenant data isolation. In the forthcoming episodes, we’ll deep dive into the details of implementing the different patterns usign Spring Boot, Spring Data and Liquibase.
En energigivande kickoff i Omberg
// Katarina Askdal
Varje höst har vi en av våra viktigaste aktiviteter på Callista, nämligen höstkickoffen. Då ser vi bl.a. tillbaka på det verksamhetsår som gått och planerar för det nya. Vi brukar även kompetensutveckla oss inom diverse heta ämnen samt brainstorma fram grundidéerna till vår årliga utvecklarkonferens – Cadec. Men framför allt så ses vi, bägge kontoren, tillsammans. Och i år gjorde vi det igen, IRL, men med lite annorlunda stuk.
Project Reactor - Reactive Programming with Spring, Part 2.
// Anna Eriksson
This is the second part of my blog series on reactive programming, providing an overview of Project Reactor, a reactive library based on the Reactive Streams specification. Part 1 covered an introduction to reactive programming.
Ny utsikt - samma adress
// Katarina Askdal
Nu har även Callista Stockholm flyttat till nya lokaler. Vi gjorde som kollegorna i Göteborg och flyttade inte särskilt långt. Vi uppskattar verkligen vårt centrala läge, så nu hittar ni oss några trappor upp i samma fastighet - Drottninggatan 55.
Using Metrics To Manage Risk in a CD Environment
// Martin Holt
Working in a continuous delivery environment can feel a little daunting - any changes you make will be rapidly delivered to your production environment. Although the intention is to provide immediate benefit for your customer, without proper risk management there is a real risk of exposing bugs and triggering outages. In this blog post I will look at one strategy that uses metrics to reduce those risks.
Optimizing a simple ray-tracer written in Go, part 2
// Erik Lupander
This is the second part of my mini-series on how I used the go profiling and built-in benchmarking tools to optimize a naive ray-tracer written in Go. For part 1, click here.
Optimizing a simple ray-tracer written in Go, part 1
// Erik Lupander
In this 2-part blog we’ll take a look at how I used the go profiling and built-in benchmarking tools to optimize a naive ray-tracer written in Go.
Technical aspects of ontologies, part 2
// Björn Genfors
So, what is an ontology? In the broadest sense, an ontology is knowledge representation, symbolically encoded as to allow for computerized reasoning. Simplified: to use the terminology from the previous post, an ontology describes concepts and their relation to other concepts using a formalized language. This enables powerful computerized “thinking”, but creating a well-formed ontology is a big task.
Technical aspects of ontologies, part 1
// Björn Genfors
Many are the situations where there’s a need to organize information for subsequent use, and one way to do this is to use a controlled vocabulary. This need may arise in a limited setting, where your requirements can be managed off the cuff, or it could arise in a setting where secondary use of information is foreseen but exactly how is unknown. In these more intricate circumstances, an ontology may serve you well.
Nytt kontor i Göteborg
// Jan Västernäs
Vi har flyttat till nytt kontor i göteborg. Det var ingen lång flytt, från 2:a till 6:e våningen i samma byggnad. Adressen är alltså oförändrad och den invanda vägen till AfterCadec behöver inte programmeras om. När det blir konsert på Ullevi igen så kan vi kika in lite på dem också :-) Den stora öl-kylen har också flyttat med. En flytt är ju annars ett bra tillfälle att rensa upp och slänga, Tipptapp-appen har vi använt ett antal gånger.
An introduction to RSocket
// Pär Wenåker
RSocket is a new communication protocol that promises to solve the issues we have with HTTP, and together with that, it might also simplify the way we design and build distributed systems and microservices. I will come back to that last statement in a later blog post.
Blog Series - Reactive Programming with Spring
// Anna Eriksson
This blog series will serve as an introduction on how to build reactive web applications using Spring Boot, Project Reactor and WebFlux. It will be a beginners guide to the reactive world, but the reader is assumed to have previous knowledge of Java and Spring Boot.
Part one provides an overview of the different concepts behind reactive programming and its history. Part two serves as an introduction to Project Reactor with a lot of short code examples. The upcoming blog posts will cover WebFlux (Spring’s reactive web framework) and R2DBC (Reactive Relational Database Connectivity).
An Introduction to Reactive Programming - Reactive Programming with Spring, Part 1.
// Anna Eriksson
This blog post provides an overview of the different concepts behind reactive programming and its history.
Certified Kubernetes Application Developer (CKAD) exam preparation tips
// Magnus Larsson
Last week I passed the CKAD exam (Certified Kubernetes Application Developer). In this blog post, I will share some preparations I did to be able to solve the tasks in the exam, specifically on how I prepared for the time constraints in the exam.
Kafka Authorization as a Graph
// Björn Gylling
In this article, we describe an open source tool that makes it possible to visualize access control lists in Kafka to help you get an overview of how access in a Kafka cluster is configured.
Dynamic Lists with Asynchronous Data Loading in SwiftUI
// Anders Forssell
SwiftUI is an exciting new way to create UI on Apples platforms. But it is still a young technology and it can sometimes be hard to find information needed to support the implementation of more advanced use cases.
Presentation på React Meetup Presentation
// Jan Västernäs
Presentation från Meetups
Stephen White pratade på React-meetup förra veckan kring “React Native with a twist of AWS”.
Håkan Dahl "AWS Certified Solutions Architect - Associate”
// Jan Västernäs
Vi jobbar ju mycket med kompetensutveckling och satsar i år på att dokumentera en del av våra kunskaper genom att genomföra certifieringar. Några områden som är intressanta är tex AWS, kubernetes och SAFe.
Har vi fortfarande samma problem?
// Mikael Lagberg
Vi på Callista gillar att prata om saker som ligger i teknikens framkant, vi gillar att jobba med saker i teknikens framkant. Det finns dock saker som inte verkar försvinna oavsett hur ”långt ut på kanten” man är. I år gick jag inte på de stora “heta” ämnena om bland annat Microservices, Containers och Java updates på Jfokus 2020. Den här gången kände jag mig mer intresserad av att få inspiration kring hur man hanterar problem som man nästan stöter på dagligen.