Questions tagged [legacy]

Questions about legacy languages, code, or applications.

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vote
3answers
199 views

Microservice integration with an external legacy system

We are decomposing a monolithic legacy system into microservices. As we do so, we can't completely remove reliance on some of the data in the legacy system that's required for each microservice. ...
2
votes
1answer
98 views

Wrapping a legacy project in a test framework

I am working on wrapping an old project written in C# in a test framework. The largest problem I have is that I have a bunch of classes that are all VERY tightly coupled with other classes. All of ...
3
votes
5answers
323 views

How do you assess the damage in a system that has been using floats or doubles for money?

I've been assigned to a code base responsible for millions of dollars of transactions, per quarter, and has been in use for over a decade. Sifting through the solution, I see doubles used everywhere ...
-3
votes
1answer
33 views

Best Practices for Building An API and SDK for a Legacy Application

I have been given a task to take on a legacy application (which has a very poor API in terms of user experience, is undocumented largely, and performs slowly) and build a new API and SDK to improve ...
3
votes
1answer
189 views

How to modernize large legacy Fortran program? [duplicate]

Problem Background Recently, I joined a government agency as a software engineer/scientist/analyst. Previously, worked in software industry - gained 3 years of software engineering experience at ...
23
votes
7answers
2k views

Does adding unit tests make sense for well-known legacy code?

I'm talking about unit tests in the TDD sense. (Not automated "integration", or what you like to call it tests.) Legacy code as in: (C++) code without tests. (see: Michael Feathers' Working ...
2
votes
1answer
190 views

Is it possible to layer an API (REST, GraphQL, etc.) in front of data that is currently only accessible via an enterprise desktop GUI?

Currently, my thoughts are that GET requests would be feasible by using the concept of screen scraping combined with a cron job that runs at a set interval to scrape data from the GUI and sync to my ...
4
votes
1answer
216 views

Is stateless mode necessary before containerizing a monolithic application?

In my team, we are maintaining a monolithic application that was started in 2003. It is written in Java and has seen several successive layers of technical changes, growing to a hefty 400k-line ...
8
votes
3answers
866 views

How do I write unit tests for legacy code (that I don't understand)?

Forward I've read a lot of things before asking this question, including many relevant questions right here on SE: (Software Engineering SE) Writing tests for code whose purpose I don't understand (...
144
votes
5answers
48k views

What are the key points of Working Effectively with Legacy Code? [closed]

I've seen the book Working Effectively with Legacy Code recommended a few times. What are the key points of this book? Is there much more to dealing with legacy code than adding unit/integration ...
14
votes
3answers
6k views

Is Poor Man's Dependency Injection a good way to introduce testability to a legacy application?

In the past year, I created a new system using Dependency Injection and an IOC container. This taught me a lot about DI! However, even after learning the concepts and proper patterns, I consider it ...
1
vote
1answer
861 views

Should I Microkernel or Microservice my legacy ERP?

I have been working on an n-tier monolith application for a couple of years, and want to build a plan to transform this big ball of mud to a more maintainable system. I came across Software ...
1
vote
1answer
249 views

Strategies for managing legacy data for a medium sized enterprise

I work for a mid market manufacturing company with around 1700 internal employees and about 7000 external users (employees of our customers). We grew through acquisition which means we have many ...
2
votes
1answer
363 views

With source code lost, can the binary be released as MIT without it? [closed]

I preserve old software by asking copyright owners (often one author) to release the source code under an Open Source License, GPL or MIT. In many cases the source is gone, but the binaries still ...
3
votes
2answers
137 views

How to convert multiple Git repositories for related code into proper branches/tags

Background I've recently become the technical lead/senior developer for a small R&D/data science team. I've got a decent amount of non-lead experience in bigger development teams, but I've not ...
69
votes
11answers
5k views

Best Practices for Handing over Legacy Code

In a couple of months a colleague will be moving on to a new project and I will be inheriting one of his projects. To prepare, I have already ordered Michael Feathers' Working Effectively with Legacy ...
14
votes
6answers
3k views

What are the best practices around retiring obsolete database columns? [closed]

I'm designing an application which will in an early stage collect data A, B, and C from clients, but later on will instead collect data A, B, and D. A, B, C, and D are very related and right now ...
5
votes
2answers
542 views

How to approach this legacy Java project? [duplicate]

Edit: Assume that I will stay on this project until "the end". The Problem I'm currently working on a legacy interesting Java project(s).  A full rewrite is currently out of the question, as I am ...
2
votes
2answers
124 views

Make sense out of automatic information gathered from legacy system

I have a legacy system I need to plan a migration for. It's mainly developed in Ingres+4GL (an old Ingres based form system). I have the following information: Data Structures (data base relations ...
4
votes
2answers
826 views

Introducing TDD in a legacy product

I'd like to introduce test-driven development practices in an established legacy product. As with most legacy products, we could use quality improvement via safe gradual refactoring/code coverage and ...
160
votes
4answers
57k views

What is an Anti-Corruption layer, and how is it used?

I'm trying to figure out what the Anti-Corruption layer really means. I know that it's a way to transition/work around legacy code or bad APIs. What I don't understand is how it works and what makes ...
1
vote
2answers
2k views

What pattern for implementing multiple interfaces on the same type?

Description of the environment: I am implementing a (hobbyist) modern engine for (an old) PlayStation 1 video game Graphical data is represented as packets where it can represent either a polygon or ...
3
votes
3answers
371 views

Designing new system to replace legacy: Would you start with a new database and maintain both independently until the switch? [closed]

We have a legacy system which will eventually be deprecated, at which point we will switch to using a new system. What are the pros and cons of maintaining separate databases for the old and new ...
24
votes
5answers
7k views

What issues lead people to use Japanese-specific encodings rather than Unicode?

At work I come across a lot of Japanese text files in Shift-JIS and other encodings. It causes many mojibake (unreadable character) problems for all computer users. Unicode was intended to solve this ...
4
votes
5answers
5k views

Why should you document code? [duplicate]

Possible Duplicate: “Comments are a code smell” I am a graduate software developer for an insurance company that uses an old COBOL-like language/flat-file record storage system. The ...
3
votes
3answers
698 views

Questions to ask a developer about legacy code before they leave? [duplicate]

We currently have over 300 web projects that are legacy code, that is kind of spaghetti like based on a modified version of an old framework. Our one developer that knows these systems best is ...
0
votes
2answers
172 views

Advice on using middleware to phase out legacy ERP system

I would like to know if any of you have any experiences and advice you'd like to share about middleware systems? A little background first: the company I work for is based entirely on a closed ...
5
votes
5answers
2k views

How are financial organizations planning for the degradation of old programming languages such as COBOL? [closed]

I know that some financial organizations still use "dead" languages such as COBOL. I'm wondering what will happen in the future, when almost no one will program in those languages, and the maintenance ...
14
votes
3answers
316 views

Supporting development for older OS

I am maintaining a large portion of legacy code, written in C. This code was initially written to be comiled against Windows 3 for Workgroups, and later a version for NT was created. This legacy ...
28
votes
8answers
4k views

What are the advantages to developing with outdated technologies? [closed]

A little background: I am working at a large company, using Windows XP and coding Winforms in VB6/VB.Net and some WebForms in VB.Net (95% maintenance code). I have one 4:3 19" screen. A more modern ...
5
votes
4answers
794 views

Code cleanup methods and/or code coverage tools

I have an application at work, which I started work on about 7 years ago. This was my first engagement in ASP.NET web applications, and coming from a Win32 background I had a hard time adjusting. ...
11
votes
12answers
3k views

As a young developer, should I be worried about having to use “out-of-style” tech at work? [closed]

I'm a recent college graduate (last May!). While I was still in school, I wanted to make sure that I had a job before I graduated, and very early (probably too early) in my job search I settled on one ...
2
votes
1answer
250 views

Working with a large, messy object [duplicate]

I have been handed a very cluttered, "One Ring" object (one object to rule them all). The OR class has 40 fields. These fields map to 16 different objects (the OR has all the fields from the 16 ...
52
votes
5answers
3k views

Does dedicated maintenance work hamper a programmer's career? [closed]

The majority of my work over the last three years has largely been around maintaining legacy systems that needed patching up or the occasional revamp before being sold again. I understand the ...
3
votes
2answers
750 views

Repository pattern and Dependency Injection without an ORM

I want to implement the repository pattern in an old legacy project. I already did some research, and found that, without an ORM, it's completely acceptable to have methods like "GetBySpecialProperty"...
9
votes
5answers
2k views

How to understand and debug legacy software? [duplicate]

Possible Duplicate: I’ve inherited 200K lines of spaghetti code — what now? Not long ago my company placed me in a team that deals with some of the most complex bugs that are in production. The ...
13
votes
5answers
696 views

Broken Old/Legacy Unit Tests

I work for a big company and I'm responsible for a large java application with thousands of junit tests. Since I moved to this role, there have been 200-300 broken tests (likely broken for years). ...
7
votes
2answers
831 views

Going TDD in the middle of the project

They want us to develop new features of a product with TDD. I know that they don't usually write tests for legacy code of already developed modules. But yet, what if new features have to be added to ...
4
votes
0answers
97 views

Architecting an account system for oauth that bridges a new and legacy system

So this question is specific to implementing auth in our system but I'm looking for high-level (just the architecture) solution or advice on which direction to head towards. Overview (TL;DR) Our ...
3
votes
2answers
4k views

Converting static utility class into singleton

In company where I work we have lots of "utility" classes, each has lots of code inside (thousands of lines), and they are all static. And one static methods call anothers. The problem here is that ...
0
votes
0answers
186 views

Integrating legacy application with new functionality

We have a legacy application with, among other things, the ability to create instances classes within VB6 DLLs dynamically and call methods with varying signatures. We have no way of accessing the ...
15
votes
9answers
2k views

In the aggregate: how will we maintain legacy systems? [closed]

NEW YORK - With a blast that made skyscrapers tremble, an 83-year-old steam pipe sent a powerful message that the miles of tubes, wires and iron beneath New York and other U.S. cities are ...
0
votes
1answer
120 views

Access Database Migration: Sharepoint or Custom solution [closed]

In order to migrate a local Access database and make it available on-line I'm considering two solutions: Migrate the database to SQL and build a custom ASP application in order to add/edit/delete ...
-1
votes
1answer
228 views

Best solution for future maintenance of a website with hardcoded ids, custom CMS using bad database design [duplicate]

Recently I was put into a position of a tech-lead on a very interesting project that I have been partially working for two years. This project carries a lot of legacy stuff with it even though we try ...
6
votes
3answers
1k views

Working with legacy code - introducing an external BDD integration test harness

Here's the scenario. There's a large, organically grown application written in some language and manner that makes it difficult to test. It works but is hard to maintain. Specifications are woolly, ...
3
votes
2answers
1k views

How to Keep Track of Thread Safe Code in a mostly Thread Unsafe Legacy Rich C++ Code Base

For large legacy C++ code bases, notions like Herb Sutter's "const means threadsafe" don't seem to help much, because there can be an overwhelming amount of code in const functions which are modifying ...
2
votes
1answer
346 views

Best practice for accessing data from an external legacy ERP system

I have an architectural problem, and would be glad to receive some consultancy :). The application I am developing (let's call it system A) is responsible for management of work groups, where these ...
17
votes
4answers
10k views

Classic ASP to ASP.net or ASP.net MVC

We have a web application which is developed in classic ASP and it evolved over 5 years to its current form which has 100's of pages, huge database and more than 10000 active users going through at ...
5
votes
3answers
2k views

Inheritance vs containment while extending a large legacy project

I have got a legacy Java project with a lot of code. The code uses MVC pattern and is well structured and well written. It also has a lot of unit tests and it is still actively maintained (bug fixing, ...
1
vote
1answer
421 views

What is the most efficient method in converting AutoLISP legacy code to C#?

I am engaged in a project that works mainly in AutoCAD to design and manufacture prefabricated building components such as roofing trusses. One of our goals is to redesign a program that was written ...